Marble Queen changed color

I got this Marble Queen cutting as a gift, it only had 3–4 leaves at the time. Originally, it had a minty variegation, as you can see, and when it produced a very light leaf with less green, it was almost white.

At some point it stopped growing for a while, possibly due to winter or changing conditions. Recently, it started growing again, but now the new leaves have a creamy tone instead of white.

Could this be related to the fertilizer I started using, or the occasional silica? Which coloration should be considered "normal"?

Don’t get me wrong, I like both, and I like it even more that one plant shows both. I’d just like to better understand the reason behind this change.