6007838bb2
With the popularity of dark themes, and the fact that our default theme
is dark, make the initial background color (before the program fully
loads) a darker shade of grey. {0.25f, 0.25f, 0.25f} versus current
{0.55f, 0.55f, 0.55f}. Also set Windows class background brush to the
same color to remove a potential flash.
Pull Request: https://projects.blender.org/blender/blender/pulls/115968