Weird pufferfish color changes

[hi_0703]

Hi, I just got my GSP recently and yesterday the colors of its skin started to change. Like the colors were normal during 8pm-10am and it became silvery white during 11am-7pm (The color changes only appeared on the sides, the top is always a normal shade of yellow). Additional to this, his skin seems to be bumpy, which looks like it has scales but i read that GSP are scale less fish. He eats normally and its diet is dried shrimp and a feed it shelled live shrimp to prevent overgrown beaks. He's really active but its tank is kinda bare with only a cave and sand (i am currently accumulating/adapting my java fern to brackish water so i can't put it in now.) Is it normal/ok

[Pufferpunk]

Many puffers camouflage themselves to their surroundings. They also change hues when eating or sleeping.
All puffers have spins. GSP's are tiny.