Random line colors.

[elysch]

When a graph is really big, it's difficult to follow the lines. It was a great improvement the feature to use random line styles, but it would be even better if there where an option to use random colors too.

If I'm not mistaken, there is no configuration option to use random line colors.

This was discussed in issue #531.

Thank you very much for all your efforts.

ELY: I tried this one and liked it. There is no problem if you like other colors, ofcourse.

(The "static" keyword makes the value to be kept between function calls, so it always takes the next color, in the order of the "swtich" structure)

NERIDERC: We don't really know where arrows are heading as we create them, so it may not make a difference deliberately doing one colour after the next or just using a random selection from an array. I'll have a play and see what works well.

[Neriderc]

Oh good catch! I had thought we had an issue for this but it seems I never got to creating it.