I agree with this, there are a few problems such as it being rather small but there are a lot of worse things you could do of done but didn't! Make sure you take Frozen's comments into account, they are all very true comments.This is actually pretty good for a first map.
Why do people use gray for floors and also gray for walls? I always thought it was gray floors, orange walls. I mean it doesn't matter much which one exactly, just use a texture that's a bit more different than just a bigger grid for walls I'd say.
Orange for walls? That's a nightmare on the eyes.
Grey is suited towards neutrality, usually indicating an area belonging to neither team. Plus it's easier to spot players against a dull, shaded background, rather than a vibrant one where they would just blend in.
It also was never once mentioned on my own map like a year ago so I dunno why it's suddenly the worst thing to say :v