Could a tooltip be inserted for colors' numbers in Format Panel like tooltips of B, I, U, S and T? I sometimes need the numbers and want to learn them without putting a color tag in message area.

Well Cookie has written a nice long reply about the colours and that, and there is an attatchment of all the colours and their hexadecimal values too.  The numer from zero at the top line.  The plus window ones don't go up in number order as they appear (there aren't the 68 possibilities there) but you can do it from cookie's attachement, plus handles all of the numbers correctly, just it only shows most.  I know it isn't exactly what you want, but it is also nice for learning and I thought you might like it.