@Maggie agree!
I think Under 2 is a little early to know colors when asked. My son did this when he was 2. Then he could identify secondary colors first which I thought was weird and I hadn’t really been focusing on teaching those. He couldn’t identify primary colors for awhile. I think it’s too early to be concerned.
She’s way too young to be worried about any of this. My daughter turned two in November and still say every thing is purple and pink- probably because it’s her favorite colors.
She might be color blind. It’s a lot more common than you think… off the top of my head she should be old enough to do a test most likely your pediatrician can do it if not, then of course an eye doctor