Providing some photos will help.

Let's just paint them ......................and paint them BACK to the dark gray color when you leave. MY lord.: ) Every dime you spend trying to get around painting is just setting money on fire for a hideous dorm style rental screaming result. Go to a PAINT store. Buy pizza for some friends. Pick a color. Have a paint party. Do the same when you exit.

Unless your result is hideous? Your landlord may not even CARE. Forget red, purple, screaming orange etc.

Very large artwork and bright lighting to show it off will help. Don't jeopardize your deposit. I suspect your landlord thinks the dark gray is terrifically fashionable and doesn't want "landlord beige" or the lighter off whites that are trendier in some areas, but who knows? You can always ask about painting it a color of your choice, then repainting with the dark gray when you move out. Ask, never assume.

Pictures are always good. We need to know what your furniture colors are too.

https://1s3grw11kyaa3bgtpp2bkt0t-wpengine.netdna-ssl.com/wp-content/uploads/sites/35/2019/04/Villa-Kitchen-10-663x495.jpg

This shows the basic color but mind you it was professionally done and they brought in extra lighT. It is NOT this bright in there. Dark gray walls white trim and beige carpet (don’t know what they were thinking)

https://1s3grw11kyaa3bgtpp2bkt0t-wpengine.netdna-ssl.com/wp-content/uploads/sites/35/2019/04/AB-Kitchen-Best-663x495.jpg

Another photo