My son has cortical vision impairment, and in his infancy he was actually diagnosed as legally blind. Bright yellows and orange shades were the first things he showed any hint of seeing, so I made him a quilt with high contrast and lots of orange. I'll see if I can dig up a photo of it.
You may need to get more information about what your friend's condition actually is. There are different manifestations of color blindness, and what works for one may not be what others experience.
RST
not the best shot, but you can see quilt on wall
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