Is my fish a marble??

[LittleFish2012]

Hey people! Alright, after observing my betta, Ghost, I've noticed something different about him... At first he was absent of most color except for some black grizzle, so I figured he was a cellophane betta. I've only had him for two months and noticed significant changes.
The first photo is when I just got him.
The second is one month later- so you can see his body.
The third and fourth show how he is now. He is fairly dark.

I do understand the marble gene and how it works, but I'd like at least a second opinion. I've never had a marble. And I definitely didn't expect him to marble out because all the marble bettas I've heard of were colorful, not clear.

[Gracie8890]

Thats definitely a marble! Not all marbles start out colorful! But he may surprise you and become colorful!

[LittleFish2012]

I was actually hoping he'd stay cellophane. I never thought I'd find a marble.

[Gracie8890]

Aw, maybe you could find another cellophane! However i usually see cellophanes change to marbles but it could just be at my pet shop. All of the cellophanes here are marbles.

[LittleFish2012]

There aren't many cellophane bettas around here. Maybe someday.
Since all I really see is black covering his body, do you think that's the only color that will marble? Like, I see no reds or blues, so he won't ever marble that way, right?