Is the problem really that there are colors, or that the colors used don't work well for colorblindness? Do you find coloring that doesn't go afoul of your particular type of colorblindness still less useful than no coloring, or is it just that so often little attention is paid and an assumption is made that it's no worse than monochrome when in actuality it sometimes is?
I guess my real question boils down to if whether the author tried to make the default color profile at least not horrible in some respects for most colorblind users, would you still think defaulting to color is the wrong default?
From my experience as a colorblind person, the use of color to convey information falls into several categories.
1. It improves the presentation of information. The vast majority of colorblind can still see color. In this respect, we are no different from people who have normal color vision.
2. It has no impact upon the presentation of information. In these cases, the colors may not be distinguishable but there are other cues that convey information. I typically think of these cues as context. An example of context relevant to to exa is the column or character used to represent the information.
3. It degrades the information being presented. In addition to there being different types of colorblindness, each type seems to be variable. That is to say that most colorblind persons aren't actually blind to a particular color, they are simply less sensitive to that color. This means that they may be able to see a color if it is intense. Using colored text is really bad in this respect since it is typically less intense, likely due to a small number of pixels being illuminated. This reduces the legibility of text to varying degrees.
4. It makes information illegible. This is essentially the extreme version of case 3. This happens when the contrast is so low that color is the main distinguishing factor, so it may be nearly impossible to distinguish two adjacent colors (such as foreground and background colors for text).
Take anything that I say at face value. It is largely based upon personal experience. The only thing that I can say with certainty is that colorblind people see color differently. I suspect that people with normal color vision suffer from similar issues to colorblind individuals. It simply manifests itself in a standard way so that there are standard design methods to avoid it. Of course colorblind people throw a wrench into the works because their vision is calibrate in different ways due to their sensitivity to each color.
Does it not make sense for the colourblind person to adjust the colour definitions for their terminal, so all programs give acceptable output? Just as a myopic person may increase the font size.
I don't think it's colourblindness, but I have trouble reading ANSI blue, which xterm defaults to rgb(0, 0, 238). I've changed it to be a roughly Persian green colour rgb(0, 166, 147).
If I had the most common male colourblindness, I'd probably add some orange to the default reds.
Sure, I'm largely aware of how colorblindness works (my father is colorblind and my friend is colorblind and I've discussed it multiple times with each). I'm really looking for whether experiencially you, or the root comment, have experienced good color schemes that work well within the constraints you impose, and whether that alters the statement slightly from "it should not default to color" to "it should not default to color unless done well".
I understand that the answer may be different for different people in somewhat non-subjective ways, since there are different types of colorblindness.
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.
Point 4 is the overriding problem. I have never been able to find a color scheme that works acceptable for text on light background and for text on dark background. It is virtually impossible to find a good pleasing and legible color scheme that works just on text on a light background.
Is the problem really that there are colors, or that the colors used don't work well for colorblindness? Do you find coloring that doesn't go afoul of your particular type of colorblindness still less useful than no coloring, or is it just that so often little attention is paid and an assumption is made that it's no worse than monochrome when in actuality it sometimes is?
I guess my real question boils down to if whether the author tried to make the default color profile at least not horrible in some respects for most colorblind users, would you still think defaulting to color is the wrong default?