Okay, see if THIS works for you... I have the layer of the "Brushes" set to Multiply (look in the Layer Stack and you should see where it says Mode - Normal, well hit the down-arrow and among the tons of modes, find Multiply (kinda near the top) and what that will do it show only the pixels darker than mid-tone (125 value). This, BTW, is also what you do if you are coloring for comics - you place the inks at the top, and set the mode to Multiply and paint underneath.

Okay, new layer on top - mode - Color. Paint a color you want the fabric to be - I used a fairly vibrant Blue. At this point you'll see the blacks go kinda mushy - at the bottom of the Layer stack, you'll see an icon that is a split of black and white - these are Adjustment Layers (AL) - click on it and choose Levels. Put it in the stack above your Brushes (but below your Color Layer). Hold the Alt key and click the line between the Brushes and the AL (and you will notice the cursor will change when you do this) - this links the AL (anything really) to the layer below so it ONLY affects the layer linked. Adjust your Levels (just double-click on the layer and the dialog box will open) to make it more contrasty - just pull in both left and right arrows to taste. This will make it more punchy.

NOW, since it still didn't look too "rich" I created an AL above the Colors layer and not only made it more contrasty, but I clicked on the little RGB at the top of the Levels Dialog Box and chose Red - pulled in the right and middle arrows to give a red sheen. Now here's the tricky part - make sure you click on the white box next to the AL layer icon in the stack, and hit Ctrl+i to "invert" the mask to black. This hides everything on that layer - why on Earth did I do this?

Get your paintbrush out, make sure you are painting white, and paint in where you want "highlights" to be in the fabric - this will make the highlights "punch" as well as give them a specular sheen that is a little on the red side, and looks a bit richer.

Once you've painted where you want all the highlights, open the dialog box again and feel free to make more changes - add more colors, etc.

It doesn't have to stop there - you can create as many ALs as you want, each for a different purpose - more highlights, even brighteneing spots of the shadows, specular colors, whatever you want - you can stack them infinitely to achieve the final look you want.

...Can you see why us Photoshop folks kind of "snicker" when we read about people who claim you shouldn't have to use any post work - that a software's renderer should be enough and you should just work harder to make it do what you want...?

Hope this helps - and lemme know if this isn't quite what you're looking for - I'll come up with something else for you.
-Lew ;-)