Rework the roadmap coloring scheme

[oleg-nenashev]

Follow-up to comments by @MarkEWaite in #2957

Could we consider using the background color from the "Future" for the "Current" cells so that the higher contrast background is on the current projects? I find it much more difficult to read the "Current" column than the "Future" column because of the lower contrast difference between "Current" text and "Current" background. The background color behind the "Future" column makes the text very easy for me to read.

My suggestion: use color scheme for additional categorization and search, e.g. splitting stories for target audience:

• Jenkins users
• Jenkins administrators
• Jenkins developers

[code2x]

It seems the issue is current open. /assign