What do you guys think? They might be a little on the big side. The way I see dragons is having a more flexible size range than in the books. These show around the large sizes for the colors, but the smallest average color would be the dragon down from the shown color. Like a small bronze would be the size of the brown. A huge brown might be a little bigger than shown brown, maybe the size of a middle sized to smallish bronze. I belatedly realize that I didn't draw a minimum sized green, but imagine that the small green's head would roughly be touching the largest green's cheek. The colors tend to have about a dragon's head difference at max or minimum size in comparison to one another.
I'm allowing this flexibility in dragon sizes so that browns can be more likely to catch queens, and so that bronzes don't crush their green mates during mating flights. =P

*The male image is a modified image of a clipart I found. I silhouetted it and modified the shape, and made the female from the male model.
Human sizes are shown at 5 feet, 6 feet and then somewhere in between. If you guys want to have a size reference with your character and your dragon together, I can whip one up for you. We just need to figure out on a scale of 1-10 how big your dragon is in the size range (the feet thing is just too awkward to use any more) and then take your character height and put them together, and that will give you a rough idea on the size reference.