If anybody wants to change the loading bar color from dark red to their favorite color, go to your game's
Data folder and open the
Menu folder then the
Data folder within it.
(ie: ... Data\Menu\Data)
About half way down are two files, one called,
progressbar_fill_texture.dds and the other is
progressbar_fill_texture.tga.
Use your favorite graphics editor (Paint.NET in my case) and change their colors to your liking then save 'em.
I don't know why there are two files for this feature but, it is recommend that you change
both the .dds & .tga files to exactly the same color whichever color you choose.
I chose yellow because of two reasons actually.
First is because I'm a little hard of seeing and second is that it's my favorite color.