greenies not so green

Remember the sulphureas? They've turned out to be quite moody. As briefly mentioned before, we've had summer temperatures and lots and lots of sunlight for several weeks. The sulphureas decided they don't need to deal with this and just went into mid-summer stasis. They're still healthy and firm, no worries there,  but I'd like them to grow, not sleep. Funny thing, I had a couple of weaker sulphureas standing in the corner of the window so that they get less sun and they've grown a lot since then. Now I've moved the rest there as well. Hopefully they will like the new location more.
 I find the color difference very curious (check out the same plants from the older post).