As any professional designer should understand, it’s not that simple. Even if you (a designer) are not colourblind, over 8% of your male clients are likely to be, as are 8% of their male target markets (colour blindness is rarer in females — more like 0.5%). If your design work is unsightly or hard to read for this substantial group, you’ve made a pretty huge mistake.
Are you colour blind?
If you see the text “SAVE 30%” in the image above, you’re in the clear. If you see something peculiar (or nothing), then we’ve got some bad news for you: you are red-green colorblind. If you’re not convinced, you can take a full test here.