I've found another problem with prince and gnuplot svg files
run this to test it:
prince http://www.alexmac.cc/gnuplot2.svg test.pdf
One of the paths gets coloured cyan in prince, but purple in Safari and Illustrator (purple is what I'm expecting it to be).
Which version of Prince are you running? When I try it I don't see any cyan path, there is one red, one green, one blue and one purple, and it looks identical to the rendering in Opera.
6.0 rev 5 on Mac OSX
for me the purple path is rendered in cyan instead of purple
Sorry, I was testing with the wrong version of Prince. This problem is caused by a bug in the parsing of style attributes in SVG, which we have fixed for the next maintenance release. The issue is actually the spaces in the rgb() value, if you change it from this 'stroke:rgb( 87, 15, 72)' to this 'stroke:rgb(87,15,72)' then it should work fine. Because it wasn't correctly parsing this declaration, Prince was using the color defined on the parent group, which was cyan. Sorry for the inconvenience.
We have fixed this bug in Prince 6.0 rev 6, available now. Thanks for reporting the issue!