Discoloration, possible pest?

Is this the sign of russet mites? I got two freebies from IHG, big buffalo and both of them starting doing this though.. and I tossed the other one. Kept this one because it wasn't as bad. Or is this just genetics?
Its under a HLG 100, pure coco and fed Maxibloom, tap water. PH 5.8-6.0
My other plants don't show any of this.
Also uploaded a picture I circled when they were a little smaller.

I've had that variegation on leaves before. I don't know what causes it but it typically stops occurring as the plant gets older. Although I have had plants in the past that hade two tone leaves all through the grow. I wouldn't worry about it. But it would be a good idea to keep an eye on it and scope the underside of the leaves just in case.

xtsho said:

I've had that variegation on leaves before. I don't know what causes it but it typically stops occurring as the plant gets older. Although I have had plants in the past that hade two tone leaves all through the grow. I wouldn't worry about it. But it would be a good idea to keep an eye on it and scope the underside of the leaves just in case.

Click to expand...

That's what I was thinking, it looks like it's getting better. Also the fact that it's only the two doing it makes me think it's genetics. I got a friend telling me it's not.