Well, I was going to say Texas tortoises, but then I looked again and saw the large spurs on the front legs. Sulcata. Probably that color because they've lived their whole life indoors in that aquarium.
I actually like the dark look, too bad it won't stay always like that. Are you thinking about getting them and then rehoming? I do remember don't I, that you don't have room for sulcata?
Mine is very dark and he sees sunlight everyday ( fake and or real ) and is very very slightly pyramided. Looks like a 20 gallon tank for 2 sullies though. .... pyramided some too.