Betta Fish: Are color changes to white/silver okay?

Hi! I got this little guy in october of 2025 and he’s been awesome! He is so zoomy so the pictures aren’t the best but the first 2 pictures were from when we first got him, the next 2 are about 2 months later, and the last 2 are from this week! He had gone fully red, but now is turning a lighter color on the tail end of him. I know color changes can be normal, but not usually turning a lighter color! Do you guys think he has the marbling gene? he also developed a darker spot on one of his sides(very last picture) and i’m just curious if it’s bad. he is active, eats, and shows off for us; I have not noticed any big behavior changes. thank you in advance!