Paint-a-thon: come up with suitable technology colour palette

[fneum]

Especially in the plot balances-energy.pdf there are some technologies that are hard to distinguish, e.g.

• similar colours of green both for synfuels and heat pumps
• similar colours of red for gas and heat
• grey for transport and hot water storage
• black for electricity, gas for industry, CC

We should come up with a less ambiguous color scheme, but I don't want to propose changes alone.

[martavp]

👍 Yes, this should be done. A well define colour scheme is needed