To me, some of the blues have too much gray in them. Gray "dulls down" the color whereas usually you want bright and/or vivid colors for a child's quilt.
The greens seem too much in the same range for me -- all middle range greens. If at all possible find a really light green (or even better, a bright yellow) to add to that group, and also a little dash of very dark saturated green.
But honestly I think my biggest problem is with the two blues next to the blue dinosaur fabric; they are too grayed down. I would use the blue dinosaur fabric as the "main" fabric and then pick colors from that fabric to add to the mix -- especially some orange, red and maybe a dark brown (all colors that are int the dinosaurs themselves).
I would also take out some of the greens -- there are too many of them compared to the other color(s). I agree about taking out the green stripe for sure.
Just my 2 cents and how I would approach this at home......