In the case of text that means asking the question: does removing all color remove any information? If the answer is no, then a colorblind individual can use other cues. (While my prior post focused upon legibility, two different colors may look like the same color to me even when the text is perfectly legible.)

I would also suggest keeping the number of colors used to a minimum. More color combinations means more opportunities for problems and more difficulty in resolving those problems by setting a custom palette.

Finally, only use color when it adds value. The use of color to highlight different file types was useful. (The file extension still existed as a cue, which is great.) The use of color to highlight columns is just asking for trouble without adding value. It is not adding value because all of the elements in a column are the same color anyhow, so it adds the risk of reduced legibility without highlighting anything in particular.