Changing the playback cursor color?

Is it possible to change the color of the cursor that moves across the screen when you press play?so far can't figure out how to.my eyes ain't too great and its hard to see that grey/black line.luminescent green would be cool. Cheers.

Action list -> action "Theme Development: Show theme tweak/configuration window" Look for entry "Play cursor", clicking on the colored rectangle brings up a color picker dialogue where you can choose a new color. Don't forget to save your tweaked theme afterwards, otherwise it comes up in its original state on next Reaper start.

Changing playback screen color 

The playback screen (video screen) background is black. Is there a way to change it to a different color?

Changing the playback cursor color 

Probably the simplest way: Windows>Settings>Accessibility>Mouse pointer>Change pointer color> set "inverted" (or custom, there are many possibilities...)