I'm trying to substitute the backup altimeter from the default A321 into the Overland A320. The A321 gauge cab has a file called "altimeter_backup_background.bmp". I'm assuming this controls the background color. After extracting it from the cab using IZarc, I converted it in DXTBmp and changed the background color from black to airbus blue/gray. Once I convert back to 256 color, is there a way to reinsert it into the cab file and overwrite the original? I've tried without success. Thanks for any help.

You can't "insert" anything into a .CAB file. You need to extract the entire .CAB file to a folder, make your changes, save the file(s), then......either leave the folder alone, or use the CAB utility program to create a new .CAB file.

Alternatively, you can do the following:- In the \Panel\ folder of the aircraft, create a subfolder with the same name as the .cab file.So if the file is named Overland.cab, the folder name should be Overland- Place the new bitmap in this new folder.FSX will now use the modified bitmap in this new folder, instead the original from the .cab file.Quite a handy trick sometimes.Cheers, Rob

Interesting, thanks much guys!