sorry, wrong version of test file. the right one is attached now.

Peter Rolf schrieb:
> Hi,
>
> there is a small bug in colo-hex, which leads to slightly wrong colors 
> (at max. -0.390625%).
> In line 41 of both mark related files there is
>
> \newdimen\hexcolorfraction \hexcolorfraction=\dimexpr(1pt/256)
> .
> This should be 255 (#fractions) instead of 256 (#values); I made the 
> same error a quite while ago. If I patch the files, I get the correct 
> color in case of mark ii, but mark iv still gives the wrong one 
> (remade the formats). Mh, strange.
>
> Here the output of my beloved 'tabbyCalc' (result of operation is 
> always in next line, which is then used for next operation):
>
> 1/255
> 0,0039215686*255
> 0,999999993
>
> 1/256
> 0,00390625*255
> 0,99609375-1*100
> -0,390625
>
> I attached a small test file, which hopefully 'shows' (depends on your 
> monitor) the difference. The border line goes from the lower left to 
> the upper right corner; you have to look 'closely'. :D
> I case of pdftex you can also peek into the eps file to see the color 
> values (before and after patching). No such help for mkiv. I have no 
> clue why mkiv still gives the wrong color...
>
>
> Best wishes,  Peter
>
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