If I understand you correctly you want to remove the color from the cloths, but keep the rest colored, correct?

The easiest way is to go into the material room and find the image nodes that have the color that is applied to the cloths.  Add a cycles>converter>separate HSV and a cycles>converter>combine HSV nodes. Take the color image map and feed that output into the separate HSV.  Take 2 of the separate outputs (H & V) and connect those into the combine HSV (H &V).  Leave the S output unconnected and on the combine HSV make sure the S value is set to 0 Zero.  Finally take the output of the combine HSV and attach it to where the color image map was going.

What this does is takes any color maps and removes the saturation basically turning anything to a grey scale.  When you render the result will be gray scale with the highlights baked in.  Easy to then tint to the color you want.

If you want to do the tinting in Poser then do the same as above except hook up the S & V together and put a color chip into the input of the H input of the combine HSV.  This will give the same amount of brightness and saturation, but change the color from a red to a blue as an example.  Multi-color maps will be turning into monochrome color, ranging from black to the color of the input chip.  So if you had a Red and Green Flag, it would become a single color such as yellow if that was the input chips value. 

Poser does not have a delete this key frame and have everything move over automatically.  However, you can do the following to get the same results you are looking for.

1:  Open the animation palette.

2:  Collapse all the body parts etc. to the smallest number of items on the palette. (makes it easier to highlight them)

3:  Highlight all the keys on the third frame.  That is drag a box from the bottom to the top to highlight all the parts

4:  Click and hold the left mouse button on the top key frame and drag frame 3 to frame 2 and then release the button.

5:  Same as step 4 except now drag and highlight everything from frame 5 to frame 30.  Again, click and hold the left mouse button and drag the keys from 5 to 4 and release.

6:  Shorten the movie from 30 frames to 28 by changing the 30 to 28 and you are done.

Maybe not as easy as just deleting the frame as you were looking for but it does work.  One thing to remember is that IF you like the movement on frames 3 and 5 make sure to highlight each of those frames in order and make sure to make every part a keyframe or you may end up deleting a Key and causing the resulting animation to go off in weird directions.

I had that problem with one of my uploads.  It is not visible to anyone but you.  It took about a month before it disappeared from my view.

Also, in the image path the change button will allow you to select where to save the images too and what format to make them.  That way you can have PNG or TIF or any of the other supported formats.  If you make movies this way, allows you to setup a scene and render and save those frames to a folder just for that scene and the second scene could be stored into its own folder or combined your choice.

That is because Poser no longer deletes the images unless you tell it to.  The top where it says images path, that is where you will find the images that you create.  What you have showing is how to convert those images into a movie format if you want to.  In the past you would select a movie type and render and Poser would output all the images to a temp folder and when all images were finished it would then convert those images into the selected codex.  And if you wanted to make two different codex types then you would render those images twice or more depending.  Now you render them once and then select the type of codex you want to make, and it creates that type.  Then you can select another codex and convert those same images to the new format without having to re-render.  Space wise it takes up the same amount of room if you delete the frames afterwards.  In fact, if you really want it to perform like Poser 12 just check those 3 check boxes that are partly hidden by you pop-up. Then it will render the frames make a movie based on the option you select in the pop-up, play that movie and delete the frames.  You won't see any difference to Poser 12 if you do that.

The nice thing about the new way is that if for some reason the rendering is interrupted you can pick up from where it stopped and not have to re-render all the good frames again.  And if you have 500 frames and it gets to 497 and quits with the old method you get to redo those 497 frames again and spend that amount of lost time being updet.  The new method you just tell it to render frame 498-500 and then compile that codex.

The included content is enough to keep you busy for a while.  Then you can pick what those items that interest you.  My must have's will be different than yours.  The Galleries are filterable so you can view only what you want, except for the New Art it just shows everything.  But if you choose a sub gallery you can then filter to show only the type of software that made those images.  Or if you choose the Software then you can filter to the Genres you want.

Premium Tutorials | Renderosity

Above is a link to the videos about Poser here on Renderosity.  

Poser - 3D Rendering & Animation Software (posersoftware.com)

Link to upgrade page at the bottom list's specs.

just realized you must be on an Apple. On windows it is a simple matter of changing file types in the file/folder selector dialog box.  On Mac not sure if they give you that option.  If they don't you may have to file a ticket.

Poser now defaults to making movies from images and keeping those images.  In the past it would make the images then make the movie file and then delete the images.  You can still do that using the bottom 3 check boxes.  However, in your case you have to first choose a file location which is the image path right under the Render type.  Click the change button and then set your path where you want to save the images to.  As is normal you can also choose the type of file right below the pathway dialog box.  Standard option's PNG, TGA, Tiff, BMP, JPG, PSD.  So, you set the type of images to save to when you set the image storage pathway.

Part of the improvement in 13 is that you can now render to images (always did that but would Auto delete unless to frames) but under the video Export options choose to encode the result in several different formats without having to re-render the scene multiple times.  So, to get the same basic functionality you were used to click the 3 check boxes. Auto make, Auto delete frames and Autoplay movie. I would not recommend the Auto Delete frames as you would then have to re-render the scene again.

The other nice thing depending how you view it is that the frames are now stored along with the PZ3 file.  And you can setup a different folder for each scene, to keep things grouped together.

Not sure what type of answer you are looking for.  You say that you make boxing/fighting type scenes and that you have a large cast of figures for that, and that is good.  If you have all (most) of the clothes needed for those types of scenes, why change?  I doubt that a pair of boxing shorts really changes all that much.  And most of the changes that you might find would be in color not so much style.  Newer figures have higher resolution skins, however unless you are doing extreme close ups most of that is wasted, and in fact will tend to slow things down as more memory has to be used to hold all those super fine textures.

The grass always looks greener on the other side of the fence, and I am sure that there will be a lot of people that will tell you to get on the forever upgrade path that is Genesis.  But if you are getting the results from what you have now why change?

One other point to consider is the final render size and how many of the pixels in that final render are going to be used for your object/texture.  In RedPhantom's example above the higher texture is visible in the output as most of the screen is filled with just that image.  On the other hand, if those skirts were 20 feet back from the camera and only occupied an area of 100x130 pixels in size then both would be scaled downwards and little to no detail would be readily visible.  Think about a leaf if you did a close up of that leaf then a 2K image would be in order to convey the full details present.  However, if you rendered a forest and the trees had that texture on each leaf and there were thousands of leaves then you would get maybe 2 pixels to convey the leaf and all the detail in that 2K image would be compressed down to 2 pixels.  So it comes down to a balancing act between visible detail and render resources.  

As far as UV to image maps, A UV map (Normally) is in the range of 0-1 both up & down and left to right.  A value of .5, .5 in the UV map would be dead center of the image map.  If the image map was 500x500 then the center would be 250,250.  If the map was 2000x2000 then the center would be 1000.  The center point is the same just how many pixels there are to work with.  If the 500 image map was used to make an image of 2000 pixels then each pixel would have to used 16 times (4 times each direction).  However, if the 2000 image map was used then it would be a 1-1 rendering and look the sharpest.

If you open the animation palette on the far right side is an arrow.  Click that and the bottom option is to display the Key count in the little boxes.  So the code to do the counting is still there just that it is not displayed all the time.  So most likely Poser still does a count each time there is a change in keyframes.

As far as the slow down, the more keys you put in the more complex the math gets to figure out what the path is going to be.

above is a channel and a Key frame every 10th frame, all at the Zero point.  Also I put in one point at 75 which is about the half-way point on the time line and pulled it down.  Notice that the curve not only effects the Keys next to it, but also the 2nd set out.  Although it appears to become stable 6 points from the center that is not the case.  Each Key is Zero but the frames between those keys have some slight value change from Zero.  Even Frame 5 which has 7 keys between itself (5) and the center key (75) it still has a change you can see on the dial.  Granted it is small but it still is a change.  It appears that Poser will use all keys in a channel to try and create the Tween Frames so if your animation is 1000 frames long and you have 100 keys much more complex than the simple example above you can imagine the math involved in making a line try to flow through all those points.  And those Tween Frames are computed every time there is a change to a key Frame.

Below is the expandable color ramp with 6 colors Red 0, Yellow 60, Green 120, Cyan 180, Blue 240 and Magenta 300. I made an error in the numbers. Should be Below is the expandable color ramp with 6 colors Red 0, Yellow 40, Green 80, Cyan 120, Blue 160 and Magenta 200. The color wheel goes from 0 to 239 and at 240 resets back to 0 Red.

@ Miss B The 7 Color Color Ramp in the freebie area is the version that Y-Phil wrote his script for.  The second post of his is the correct version of that script to account for a problem in Poser that won't allow Python to make changes to a compound nodes inputs and have those changes flow into the workings of the compound node.  You also may wish to check out the expandable color ramp as it is made to more closely mirror what Blenders color ramp does.  I also have a Map Range node that Blender has that is missing from Poser but you can get the same results with my freebie.

@ThunderStone If you want a rainbow I would use the Expandable Color Ramp.  One of the options is to blend between 2 colors of the color wheel.

In the example above it just has 2 colors and does a HSV Far blend style.  What that means is that starts at a Blue color and works it's way around the color wheel towards Green. But in order to get there it has to pass through Red.  In Poser Red is Zero, Green is 120 and Blue is 240 if you were to use the HSV node to make colors. Below is the expandable color ramp with 6 colors Red 0, Yellow 60, Green 120, Cyan 180, Blue 240 and Magenta 300.  you can see those colors on the 2 edges. The bands in between are those colors and how the different blend styles effect the color shift.  I like the second (third if you count the edge colors) band in.  This is a simple gradient with the ease applied.  What that means is that the colors that define the start stop have a greater effectiveness and show for a longer time instead of being a straight gradient.

you can find more information about the blends in the PDF I included with the Expandable color ramps. The nice thing is that you can choose how many colors to make your ramp instead of being stuck with the 7 I had in the orignal version.