It is not possible to answer this one because the lighting system on the motherboard could have been blown but the damage limited to the motherboard RGB or fan system.
If it works, and you can't find problems then we can't tell what was blown but as I wrote, could be RGB lighting or fan circuits which if the rest of the machine works we can just move on since we don't use either apparently.
If 2 of my pc fans where connected to my MB, but by mistake I also connected the PSU the fans via molex, is that possible that I casued short circuit? system botted, white smoke came out, I plugged it off and realised the problem. Should I be worried or am I gonna be alright? No visible damage anywhere that I can see.
/Gigabyte B350 Gaming, Ryzen 1200, 2x4GB Fury, Deepcool 580W Psu/