Bunny my streps are weird too. They can suddenly bloom with a totally wrong color blossom and then later go back to the real color. I've also have two different solid colored blossoms on the same stem. I think the surprises are part of the fun of growing them.
I had some snapdragons planted long ago - three years ago they popped up and were beautiful, they re-seeded for a couple more years, till a draught burned them out.
Once bought innocent looking flowers - looked like mini pansies, I think they were called violas. They weren't innocent, by the next year they were popping up all over the place, driveway, flower boxes, in the grass, in gravel, everywhere. I had no idea they were like weeds here. I had to demolish them so other things could grow.