This has been fixed in the new 9.4 beta version.  We are finishing the Beta testing and hope to have it released to iFly, App, and Play stores in a few weeks.  Here is a temp workaround for a one time fix to get them to White.
    - Open iFly GPS and View a Plate, then touch the Plate Settings button and Show Fullscreen.
 
    - Now Exit and Shutdown app and the restart iFly GPS.
 
    - View a Plate or Apt Diagram, it will be in Fullscreen, so touch the Plate settings, Exit Fullscreen Mode.
 
    - Now you can touch the Plate settings button and Re-Vert or In-vert colors as desired.
 
    - In v9.3, App/Dep Plates will default to White-70% and Apt Diagrams will default to Black-70%.
 
Please note this is a workaround until v9.4 is released.  This bug is fixed in the 9.4 Software.  I hope this helps and please contact us if you need any additional help.