Change colour of Desktop Effects Track Mouse rings

Wondering if there is any way to change the rings to higher contrast colours, from the default white and grey? The settings seem to be in ~/.config/kwinrc file, but it has no colour options that I know of. It seems like an obvious choice to want to have.

The Mouse Click Animation has some great options, but it is only on actual clicking of the mouse keys (and yes I thought maybe I could set this to long duration, but it maxes out at 999 ms.