Um, I don't grow a lot of bedding type half-hardy annuals...but I do have a single deep red callibrachoa which is still quite tiny (and mine is in full sun). Mine was only planted out a coupla weeks ago - maybe a week after yours. How big was it when you planted it? At least here in the UK, the season is long and this is still very early days. I wouldn't have fertilised yet either - not for another month maybe - depending on how much base fertiliser there was in your mix (usually around 6 weeks or so). I don't think I would be fretting and worrying about moving just yet...and if, in another month or so and nothing is growing much, simply take the whole thing and sit it on an upturned pot in the sun - see if that makes a difference.

In short...I would wait and see a bit longer.

Thanks rosa. These are probably the equivalent of your P9 to 2L from the garden center so small. I also have a couple deep reds mixed in with pink lemonade, tropical sunrise, pomegranate punch, pink star, coral sun - a whole bunch of fun colors. Unfortunately they're all in the shade except for the one on the far west side.