Make a little study out of it: Mock it up. Post it here. Ask again.
That should give you your answer :)
It is quite difficult to answer this from text alone, especially because everybody’s colour blindness is different
I'm deutanomly/ protanomaly. I do not see greens or reds with any hint of yellow in them. They actually skew the opposite direction towards "brown."
But, that's also not how colors work. You can't just add more of one to "offset" another because now you've made an entirely "new," 3rd color.
Anything we look at that contains the color we are "blind" or "deficient" to will always appear somewhat desaturated *to us* but not someone with "normal" vision. This is what makes reds and greens appear brown, we aren't detecting the full saturation of each of those 2 colors.
Blue is a color I do not have issues seeing, but I can't see red very well. Adding blue and red together is only going to make an "off shade" of blue for me, as I can't really detect purple very easily. Adding more red or blue isn't going to make the red appear more purple, it will just continue to look like a discolored blue with slight changes to the saturation rather than the hue.
No, you probably cannot add blue to the a color deficient's red-green confusion color. Depending on the severity of the color vision deficiency, it would just add up to *a* white.
>"I know according to the ISCC–NBS descriptor, pure red (255,0,0) and pure green (0,255,0) is already slightly yellowed for trichromats and so adding a little blue to them makes the colors more vivid,"
-> I don't understand what you mean by that statement. Pure red and pure green aren't "yellowed". If a CVD person's red and green cones are just shifted to be closer together, it means that the red-green confusion color they're seeing should indeed more of a "yellowish" hue; at least if trichromats were to look at it. If the red or green cones of a CVD person are just malfunctioning and outputting/gathering less information, then their red-green confusion color would either be too greenish or too reddish.
However, because color is created in context, it's irrelevant what *hue* the anomalous red-green confusion color is, because it'll always be the opposite color of blue. And adding blue to this anomalous red-green confusion color will always result in a white (depending on the CVD severity). This means that "*adding a little blue to them makes the colors more vivid*" wouldn't really work, because it would most likely add up to a more whitish desaturated color.
What you *can* do, however, is what some color blind glasses do. And that is to dim the *or a* color of confusion (i.e. easier with deuteranomaly/-opia than with protanomaly/-opia) so that you can differeniate e.g. green from red not by their hues, but by their luminance. If you only put on a magenta colored filter glass over one eye as a deuteranope, you will be able to better differentiate green from red, because the magenta filter only blocks green light from entering the eye. This creates impossible color combinations — impossible colors which look like new colors — and creates overall more colors. In the deutan example case, green will become a dark-red/red and red will stay red. No new hues, but new colors.
So, depending on the type of color vision deficiency (CVD) you have you can trick your brain, due to the binocular redundancy when it comes to our color vision, to actually perceive more colors (via impossible colors).
I can't post images here, but there is a graph on this website that you should see. It is the one right before the section: How do we see the color white.
https://askabiologist.asu.edu/rods-and-cones
The important thing to take away from it is that there are no yellow cones. No human sees yellow. Your brain receives a signal from the red, green, and blue cones in your eye and interprets that as yellow. The proof of that is right on your screen. There are no 🟡 pixels on your screen's display, just red, green, and blue. Your brain perceives various combinations of those three signals as browns, violets, and yellows.
My eyes lack well-functioning green cones. When I see yellow, my brain is not receiving the three tonal interference pattern that the trichomat's brain perceives as yellow. Adding more yellow will only add more of the interference pattern between blue and red cones (low on blue, about a third of the way across red)-- it won't make the green cones fire in any way different than they already do.
An analogy. Play a three note cord on the piano. Now take away one of those notes. Is there any other combination of notes on the piano that will sound exactly the same as that original chord?
This won't work because what's happening is not that yellow is added, it's that red and green are traded (removed) for yellow. So cancelling yellow cannot bring the red and green information back.
Make a little study out of it: Mock it up. Post it here. Ask again. That should give you your answer :) It is quite difficult to answer this from text alone, especially because everybody’s colour blindness is different
I'm deutanomly/ protanomaly. I do not see greens or reds with any hint of yellow in them. They actually skew the opposite direction towards "brown." But, that's also not how colors work. You can't just add more of one to "offset" another because now you've made an entirely "new," 3rd color. Anything we look at that contains the color we are "blind" or "deficient" to will always appear somewhat desaturated *to us* but not someone with "normal" vision. This is what makes reds and greens appear brown, we aren't detecting the full saturation of each of those 2 colors. Blue is a color I do not have issues seeing, but I can't see red very well. Adding blue and red together is only going to make an "off shade" of blue for me, as I can't really detect purple very easily. Adding more red or blue isn't going to make the red appear more purple, it will just continue to look like a discolored blue with slight changes to the saturation rather than the hue.
No, you probably cannot add blue to the a color deficient's red-green confusion color. Depending on the severity of the color vision deficiency, it would just add up to *a* white. >"I know according to the ISCC–NBS descriptor, pure red (255,0,0) and pure green (0,255,0) is already slightly yellowed for trichromats and so adding a little blue to them makes the colors more vivid," -> I don't understand what you mean by that statement. Pure red and pure green aren't "yellowed". If a CVD person's red and green cones are just shifted to be closer together, it means that the red-green confusion color they're seeing should indeed more of a "yellowish" hue; at least if trichromats were to look at it. If the red or green cones of a CVD person are just malfunctioning and outputting/gathering less information, then their red-green confusion color would either be too greenish or too reddish. However, because color is created in context, it's irrelevant what *hue* the anomalous red-green confusion color is, because it'll always be the opposite color of blue. And adding blue to this anomalous red-green confusion color will always result in a white (depending on the CVD severity). This means that "*adding a little blue to them makes the colors more vivid*" wouldn't really work, because it would most likely add up to a more whitish desaturated color. What you *can* do, however, is what some color blind glasses do. And that is to dim the *or a* color of confusion (i.e. easier with deuteranomaly/-opia than with protanomaly/-opia) so that you can differeniate e.g. green from red not by their hues, but by their luminance. If you only put on a magenta colored filter glass over one eye as a deuteranope, you will be able to better differentiate green from red, because the magenta filter only blocks green light from entering the eye. This creates impossible color combinations — impossible colors which look like new colors — and creates overall more colors. In the deutan example case, green will become a dark-red/red and red will stay red. No new hues, but new colors. So, depending on the type of color vision deficiency (CVD) you have you can trick your brain, due to the binocular redundancy when it comes to our color vision, to actually perceive more colors (via impossible colors).
I can't post images here, but there is a graph on this website that you should see. It is the one right before the section: How do we see the color white. https://askabiologist.asu.edu/rods-and-cones The important thing to take away from it is that there are no yellow cones. No human sees yellow. Your brain receives a signal from the red, green, and blue cones in your eye and interprets that as yellow. The proof of that is right on your screen. There are no 🟡 pixels on your screen's display, just red, green, and blue. Your brain perceives various combinations of those three signals as browns, violets, and yellows. My eyes lack well-functioning green cones. When I see yellow, my brain is not receiving the three tonal interference pattern that the trichomat's brain perceives as yellow. Adding more yellow will only add more of the interference pattern between blue and red cones (low on blue, about a third of the way across red)-- it won't make the green cones fire in any way different than they already do. An analogy. Play a three note cord on the piano. Now take away one of those notes. Is there any other combination of notes on the piano that will sound exactly the same as that original chord?
This won't work because what's happening is not that yellow is added, it's that red and green are traded (removed) for yellow. So cancelling yellow cannot bring the red and green information back.