_**(This post's purpose isn't to bash anyone or their work, but I just felt like this had to be said)**_
Seriously, if one guy (shout-outs to you by the way, you're awesome) could give every one of Mordekaiser's skins new passive effects and colors (and a bit more in case of Lord) and even give Pentakill unique dance effects, why can't the skin team give Morde's only other 975 rp skin a recolor at the very least?
Some of the work is already done for you with the passive and the W, and if one person could make all that I mentioned above then why can't a full team of people simply change the colors of his spells if they consider making entirely unique particles a waste of time? Not to mention that 975 skins are supposed to have something more to set them apart from lower tier skins anyway according to your own guidelines, and also try to remember that one statement you made that 975 skins during reworks will only get new particles or recolors if the skin looks off without them (Like Exiled Morgana, I think it was).
And I'm pretty sure with Lord now having an awkward mix of purple and green spells (and let's not also forget the **purple** gems on his armor and mace) with the recent changes, he fits that criteria as well.