From what I recall, 24 bit is of concern, while the "32" bit is an extra 8 bits devoted to alpha channels for transparencies and whatnot. 24 bit (16.7M colors) is achieved through having (2^8)^3 vaues for red, green, and blue. The thing u see a lot with LCD's, especially those that employ TN+ films, is 18-bit color that uses dithering of some sort to create roughly 16.2M colors. This is often achieved by flashing various colors so quickly that the eye perceives them as a blend and thus as one of the colors in a 16.2M color spectrum. The color on these may not be so good. On the other hand, I believe it was LG Philips that actually had some 10bit/ channel panels to add alpha channels or whatnot.
If you get a PVA based panel though (true 16.7M colors), and especially with the new LED backlights that'll hopefully replace the CCFL tubes, color should not be a problem at all. The Dell 2405FPW was touted in some photoshop magazines for its excellent colors.