That depends on the type of color blindness. There are three basic variants of color blindness.
Red/green color blindness is the most common. The affected person cannot differentiate between red and green.
Blue color blindness is an inability to distinguish both blue and yellow, which are seen as white or gray. It is quite rare.
A total inability to distinguish colors is exceedingly rare. These affected individuals view the world in shades of gray. They frequently have poor visual acuity and are extremely sensitive to light, which causes them to squint in ordinary light.
it is different for different people
according to the trichromatic theory, color information is processed in the brain by comparing the relative activations of three different types of cone receptors in the retina. these three types of cone receptors are either sensitive to blue, responding best to short wavelengths of light, green, responding best to medium wavelengths, or red, responding best to long wavelengths. when colorblind, one or more of a person’s cone receptors may be “filled” with the wrong photopigment color. this leaves less functional cone receptors. therefore, dichromats (people left with only two types of cone receptors) are incapable of distinguishing between some or all colors, depending on which cone receptors are lost. for instance, if the green cone receptor is accidentally “filled” with blue pigment then the ability to see green is lost. that person would only be able to blue and red and their derivatives. so, the colors a colorblind person can see all depends on which cone receptor color(s) are missing.
most people are colour-blind because they can’t see the colour green, but it doesn’t show a diffrent colour, it hurts their eyes, it is a blur. They can still see it but not very effectively.
There are two types of color blindness. The one I know about, is red-green. Its where they tend to flip these colors. People who are color blind don’t technically see only black and white, they just confuse most or all their colors.
if your colour blind there are few colours you can see. Some people can’t see dark others light, It depends on what you can and can’t see. I have a friend and he can’t see fluorescent colours. some may only see grey , black and white. Some may see blue and green
Contrary to popular belief, only a rare percentage colorblind people can only see in black and white. More commonly, colorblind people difficulty telling two colors apart, or being able to identify what color an object is. Colorblind people don’t see anything “wrong”, their perception of color is just slightly different. Only in a minority of colorblind people is colorblindness a major disability.
The most common colors people have trouble distinguishing would be red from green (and sometimes brown), and purple from blue, and sometimes dark yellow with light green..