Also most changes are not for the rare total colorblindness but for the more common deuteranopia which is a red-green based colorblindness where its difficult to distinguish hues in normal light.
So common fixes are to prevent things like red print on black backgrounds and to adjust contrast or brightness levels. From what I'm tol the fix is sort of washing out many of the hues associated to red/green and going more basic where the contrast is sharper.