I believe the opposite, the reason been:
1. why would you use different protective colour for the same material, if both the green and yellow are metal?
2. composite material is used to reduce weight, if your have large portions of metal at two ends and small portion of composite in the centre would it not cause structure problem, and weight balance issues?
3. composite material use polyester resin with reinforcement embedded in them. The resin which have a yellow tint, but they are unstable under UV light thus requires a protective cover, and I think the protective paint usually come out as green (reflect uv part of the spectrum) but I must say I am not too sure about it.
4. with regard to the different shade of green in J-10 and J-11B, I believe you can fine multiple shade of green on those two aircraft. I don't know how how to upload pic so can't show you.