development

I decided to go with the design where the boys are running across the page, chasing the mysterious man. But I want to get my colour palette right before I start - all the other covers are yellow, red and black but I want to go for something different as it will stat out as a new and contemporary. 
I had a play with some colour patches:

I like the look of one really bright colour against a dark - possibly only using two colours plus white. My favourite combination is either the red, blue, beige or blue, orange, white or yellow, light blue, orange. I have used the bright orange and dark blue combination for some of my secret 7 designs and they have worked well. 

I tried different combinations roughly, and I do think the blue, orange, white works the best - it will be quite striking on the shelf as it is such a bold blue and orange I will be using and I think the colours will appeal to both girls and boys. I also did a quick sketch of what I want the mysterious man to look like:

I went for a classic bank robber look with the pointy jacket and hat, big collar and briefcase - I want to make him have quite long, pointy limbs to accentuate the sneaky, thieving character within him.