...you should NOT paint your room and lose your deposit if you are not decently-off financially.

Unless the apartment owners and managers only care what it looks like when you leave and you can afford to add a few layers of white base paint just before doing so, to avoid losing the deposit. Such policies are often clearly delineated in the lease contract, and you can sometimes negotiate leniency with the management as long as you do so in writing and have it attached to the contract pre-signature. YMMV