This contains a less hard orange and reflects the actual logo and CI colours better.
What should probably still be changed are the light blue, black and gray colours. I focused mainly on the "WTF-orange" and the dark blue, because they're the main two colours and are probably paired together the most. They have enough contrast to be distinguishable even by people with eye impairments and still don't burn your eyeballs due to the less pronounced brightness of the colours. The dark blue colour is based on the CIELab opposite to the WTF-orange colour.
Maybe we can even reduce the amount of colours since black and gray as well as light grey and white are pretty near together. Black and White could be set as alternatives to the gray and light grey colours for colour-reduced prints or plots.
Helix