DOSBox, The Random Color Glitch
 

There is a weird problerm, both in v0.72 and 0.73, where sporadically, the game I'm running will turn funny colors. (the black sky in X-Wing turned blue, the Chronoskimmer of Where In Time Is Carmen Sandiego? turned pink, etc.) This only occurs when running in fullscreen. The only way to clear the "hideous rainbow" problem, as I've named it, is to exit fullscreen, then go back in.

Any solutions will be most appreciated.

What are your settings in dosbox.conf at the very beginning under the [sdl] section?

fullscreen=true
fulldouble=false
fullresolution=original
windowresolution=original
output=surface
autolock=true
sensitivity=100
waitonerror=true
priority=higher,normal
mapperfile=mapper.txt
usescancodes=true

check which programs are running when dosbox runs as well.
You probably have some background application running that changes the pallete.

If not, try changing output=surface to output=ddraw or to overlay and see if that helps.

this sometimes happens to me too, on my notebook. no matter what output i choose

i noticed it has something to do with slow processors or other processes throttling dosbox or i dunno=S

Sometimes i cant see my typing cause its coloured over by black.

5char

happend to me when i had pure dosbox with no other processess running than xp default ones. but maybe there's something in between xp default processess? it's been acting weird since i installed fresh os there

DOSBos wrong colors in full-screen
 

Credit to gringe666 of 3 September 2009 for solving above.

Go to dosbox.conf (or whatever file you're using for configuration)
Change the part that says "output=surface" to "output=opengl"
Now dosbox should look fine in fullscreen.

Worked fine for me. There are also other options available to try.