I don't think its a drab panel at all, I think its great. It has lots of colour in it. You don't say how old your daughter is? Not that it makes any difference, as she has asked for it, she must really like it. why not let her help you chose the colours?
I don't know why you would put it together differently for a girl. I think your idea of "forest" colours is great, especially if you include some gold and purple and autumn tones as suggested. I'll bet your daughter will love it. Please post it when it is finished, I'd love to see it.