Some PLAAF Su-30MKKs were painted in aggressor camo even though they're front-line assets. There's no distinction between a front-line aircraft and OPFOR aggressor aircraft, they simply have to switch out the pilots between roles. I don't know why they didn't paint the Su-35s in PLAAF low-viz but it's not a big issue.
Well there should be little doubt in anybody's mind that those SU-35 will be fully combat ready and a part of the SCS patrol and anywhere else they might be needed, they will NOT be confined to play bad guys.