I never like the info texts on top left and top right corners in red color as they are hard to see.   To change them into white color that I prefer, I go to [DISPLAY] section in the Prepar3D.cfg (or fsx.cfg) file. Then replace the values of

InfoUpperLeftTextColorUser, and
InfoUpperRightTextColor

from 255,0,0 (red) to 255,255,255 (white).  That’s it.
One may also change the colors of other texts and backgrounds in the file with the colors of their choices using similar method described above.  The HTML Color Codes could be easily found on the Internet.