if this is the same one i did yesterday (follow the light, or something), both blues give you the option to exit, but i could NOT find the combo that let me get the qurazy quoin up in the top right hand corner.

I think the quest is named Being watched or something like that. I don't remember exactly how I did it, but you need to get the combo which will show you steps up close to the doors, climb there, and then, by clicking, change the color for some other to remove those barriers :)

ooooh i never thought doing of that! the one i did was a similar idea, so when i get to 'being watched', i'll keep this in mind!