Definitely on the people with color issues. I have some red-green issues, for most purposes it makes me horrible at choosing colors and horrible at choices involving subtle colors (picking the good produce) but rarely interferes otherwise. But a thin line of color is another matter. I generally can't tell the difference between a 1-pixel wide line of FF0000 vs 00FF00. Nor can I tell the difference of a few-pixel-wide indicator. I can't crimp Ethernet because the fine line of the coloring of the wires reduces it to not much better than a guess.

And a whiteboard from across the room is likely to be thin enough lines to give me big problems.