There are different degrees of colour blindness...
My husband is colour blind but thankfully my 2 sons are not...he has trouble with shades of browns, tans, greens, beiges, greys,...more so if it is the same value colours...if we are looking for a grey coloured rug, he might point to a light sage..that kind of thing..but he can see reds, greens, blues, etc...I would say maybe use brighter colours...