Had the same issue on my Mac`s and it was persistent, I found this solution in the game troubleshooting guide, worked perfectly, just needed to edit the cam_ext.cfg file;

Problem:
A HUD item suddenly turns white.
Solution:
* Go back and forth once between menu and game (i.e. press ESC twice).
A slight inconvenience but this way the benefits of HW 2D rendering,
such as HUD scaling and increased performance, are preserved.
* Disable HW 2D overlay/HUD with "d3d_disp_2d_surf_mode 0".

Q-6

thank you so much, this fixed it!