Color of an o-ring indicates the material it is made of, not just an aesthetic. (
https://knowledge.callapg.com/blog/oring-colors) That stated, they all sit in the same oil bath and temperature. Pressure might be slightly difference dependent but they are not in the pressurized oil distribution to the engine and transmission. In over 15 years of doing our oil changes, I've never seen an o-ring that was cut or sheared, regardless of color. My thought, errr, opinion, is that the colors aid in easily identifying
which o-ring goes in which spot: there are 2 that are very close in size, which requires attention to get them in their correct locations.
The kits I've purchased from LG and BajaRon are all black o-rings.
Make sure you lubricate the o-rings for installation on their plugs and insertion into their threaded holes. Both plugs should be started by hand and not offer resistance until the o-rings start to seat in their bores.
The metal seal washers on both plugs are the critical ones to prevent external oil leaks and should be new for each installation. That stated, I've reused them on occasion without negative repercussions.