Colored lines?

[rtd]

I like to draw a set of lines which will be used later to create piping. In order to have these appear in the Outliner, I group them. Since there are more than a few, each group representing a different system, water, electric, heat, etc., it would be good to apply different colors to them.

I've tried putting them on a separate layer - 'color by layer' doesn't work. Neither does trying to apply a material color.

Is it possible to apply a display color to lines?

[gilles]

Did you try color by material in Style window?

[rtd]

Thank you