Syllabic alphabets require large numbers of diacritics to represent all the vowels, I thought we could actually make a system similar to this alphabet chart, but the diacrtics coming in two different colors. One application of this is the enhanced Tengwar, with two groups of tether that are in different colors from both each other and from the Tengwar, the specifics would vary according to the mode. One idea is for vowel strokes to be marked in one color, if placed over/under the following consonant, and in another if marked over the preceding consonant. So syllable inintial vowels would, in other words, be marked in a different color from the rest. The specics colors of the diacrtics would vary acconidng to the color of the text and the background. For black text on a white background, the colours would be red and blue, for white-on-black text, the latter would be green.

I'm sorry, but the poll doesn't work (won't let me vote). I think there's an issue with the polls here that needs to be fixed. Anyway, my answer would have been "maybe". I really like the idea, but there are people out there who are color-blind and you have to deal with that somehow. There's also the question of what if your text and background aren't black and white. I suppose that's a minor point, but I just felt like you should have mentioned what you would do if it wasn't white on black or black on white.

My answers are very complicated, but as for other color texts and background, let's consider red on green, the two diacritic colors would be blue and yellow. If you wrote red on white the red diacritics would be black.
Basically, diacritics only come in two different colors, so only very basic color distinctions are invovled. If you can't make such basic colour distictions, then you would have to deal with that alphabet chart somehow.