What a nice cockerel. I love it when they are that age. Outstanding leg and beak color - comb looks straight. For the rest it's a bit early to tell....looks like he has a nice long back. So he is about 12-weeks?
Regarding the 'how-much-is-too-much" for chestnut, in general the favor leans toward very light cockerels. Lots of us don't want to go over the rim and have pure white-and-barred coloration on the cockerels and a number of others think of that as the ideal. I remember someplace where Punnett was quoted as saying that the cockerel was really a stunning bird - and I don't think that description (color-wise) would apply to the farthest end of the spectrum on light birds.. again that's my view - and you will certainly hear other viewpoints.
What we should be doing now, is paying a lot of attention to type, weight and disposition, health, vigor, fecundity and fertility -- color can be the icing on the cake.... Are you planning to put Cream Legbars in the show ring, or are you working to get the best birds that you can for your own satisfaction? That may determine what your highest priorities will be in your breeding program... Oh, and I still want to know how you got the picture of the horse in your avatar. :O)