Try adding this in that chimera boot.plist in the extras folder (make it look like the rest of the keys and strings)
<key>Graphics Mode</key>
<string>1920x1080x32</string>
or type "Graphics Mode"=1920x1080x32 on the bootloader screen when your computer boots up.
Not sure this works, but I'm seeing you asking this everywhere so give it a shot. If it doesn't work or screws up your screen, delete it from the plist to go back to normal.