I bought this cave for my Betta, and he likes it a lot.
Initially, it had a spot on the opening that wasnt punched out all the way, and had sharp points and edges on the inside, but i fixed those problems with less than half an hour of working on it.
Keep in mind that this cave does have green and purple paint on it--but if you look closely at the product image, it shows there too. its not too bad, and it looks good in my tank. the purple is only super visible under really bright lights, like camera flash and other strong lighting.
My betta took to this cave quickly when i added it to the tank, and even sleeps in it. it seems to be his favorite hiding place now as well, which is good...it means he likes it a lot.
Overall, im quite pleased with this cave, and so is my big guy. we both love it and i recommend getting it for your bettas or small fish/crayfish etc.