If a color blind person is red-green color blind, can they still see most shades of those colors normally?

Most: People (men mostly) with red-green colorblindness cannot distinguish browns from greens and oranges from reds. Other colors, such as blues and yellows are perceived adequately.

Altered perception: They will see shades of color in all colored objects but will but see the full range, so colors that might appear bright to you will seem attenuated to the color deficient and some colors will seem what you might term brownish. The mixture seen depends upon the depth of the color blindness in each individual. Because of this most color deficient persons adopt rather bland wardrobes.