personally, i just got into digital painting (i find the normal kind boring, no offense to anyone), but i think that both are equally important. color can set the mood for a pic, while value cannot. or, you have to be REALLY REALLY skilled to do that.
I think value can set the mood better than "color" actually...what you mean to say is that "hue or saturation can set the mood better than value"...if you take a good color photograph, and view it greyscale, there is almost no mood or atmospere lost....a lot of the times the image becomes more dramatic. Since "color" is really just is a combination of value, saturation, and hue, what type of "value" you have is really just a type of color that you have. value = color, just like saturation = color, and hue = color.
Well...if it's any help for color blind artists working digitally, painting softwares give a numerical equivalent to hues, values, and intensity.
In Photoshop, for example, if you go to the color picker, zero out "G" and "B" and 255 for "R" to get all the ranges for Red. Do the same for Green, zeroing out R instead. You can tell a colors tendency too by the proportions in the RGB numbers.
Paint tubes have number i.d.s as well along with the color name.