clearer graph colouration on annual cycle graph

[corviday]

The Monthly Indicator Graph shows the monthly mean of a variable for each climatology and model. If there is a single run for the model, four lines are shown on the graph - one for 1971-2000, one for 2010-2039, one for 2040-2069, and one for 2070-2099, like this:

This graph is reasonably clear, but in cases where there are multiple runs of one model, the graph gets very chaotic.

I daresay nobody could make heads or tails of this.

Ideally each of the eight runs would use the same colours per climatology, so all eight 1971-2000 data would be one colour, all eight 2010-2039 a different colour, et cetera. It might also help to assign the four climatologies a natural-feeling "sequence" of colours, like 1971 green, 2010 yellow, 2040 orange, 2070 red or something.