Coldgunner

It's not a one shot deal, you can do it again, just put a thin light coloured wash of acrylic paint over the wash, leave to dry then try again. You can lighten a too dark wash with dry brushing a light color over the top.

I repainted a darker colour over and it looks better. Though I may try watering it down, get it to seep in a little more.

Don't do it all when it's all wet, let it dry first.