in the material room you can select a color  and save it as a custom color. You can then select it in another material.

I've tried that but it still comes up as a different color. The color I picked in the palete shows up differently on the lekku. I guess there isn't anyway to fix it then?

I notice her lips are still picking up the right texture. What is / are the models you're using here?

If there's a MAT pose or a material collection provided, try applying that if you haven't already.  

The figure probably has an image texture mixed with a simple diffuse color.   Use Photoshop or similar to copy a large (uniform) rectangle in the image texture, then paste that rectangle to create a new image file.  Apply this image file to the Diffuse node of your hat thing, then use the Color Picker in Poser to match the simple Diffuse color as well.

Sorry I took to long to answer. I have been busy.  I'm unsure of what you mean or what your trying to tell me ockham.  What do I need to do to?

Looking at the images I would suggest the problem is the head and lekku use two different materials, its like trying to make a glass vase appear identical to a ceramic pot by just changing the colour, light interacts with both differently so they will never look the same.

If this is the problem then you could take a copy of the head material and paste it to the lekku but then the problem is the head texture will also be applied (complete with eyes, nose, eyebrows and other non lekku type features).  To get around this you could use a paint program to take a swatch of texture from the face image (eg forehead) and use that swatch as the texture for the lekku (maybe tiled to prevent stretch) - may be I've mistaken what Ockham's meant but that's my take anyway.