User Tools Windows - Customise active colour

Hi there,
I am trying to streamline my UI so I can surface just the tools I use regularly.
I am opting for a darkish/subdued/toned down kind of colour scheme.

Currently I have setup some Symmetry options panel and it is great that I can see what axis is currently active (I do want this). What I would like though is to be able to somehow change this to a colour that isn't a fairly distracting red.

Is there a way to customise the selected/activated colour?

Best regards.

User tool window context menu > Window > Button Checked Color.

Thank you very much, exactly what I was looking for.