Black?

Jamie Fraser

This must be a naive question, and I have asked something similar before, but can someone explain why there is no index colour for black? I know index colour 7 shows black on a white background and white on a black background, but often I want to but black text on, say, a yellow hatch area when the background is black. Using colour index 7 leads to white text on a yellow background which is unreadable (to me at least). I just find it very strange that black is not there as colour 0 and I have to set an RGB of 0,0,0 to get black. Any comments? I assume AutoCAD works this way...but does that make it right?

Roy Klein Gebbinck

I think the keyword here is tradition. In the days of always-black-backgrounds it just didn't make any sense to have an index for black. And when the white background came along, what could be more logical than changing the screen colour of index 7 to black? Of course there was no link between screen colour and print colour back then. And for the majority of today's users that link still isn't there. Screen colour red is not printed as red, it is printed as a black line with a certain line weight.
Confronted with your problem I would not change the colour of some of the text to black. I would change the colour of the textlayer to one that looks good on both black and yellow backgrounds and then change my ctb to make that colour print black. Alternatively you could consider changing the background of the display to 252. Index 7 now displays as black and index 2 still looks fine.

Anthony Apostolaros

Or you could use color 250, which is pretty close to black, or custom color RGB:0,0,0 (using the TrueColor tab of the Select Color palette), neither of which will be affected by background color.