Topaz and Flare Armor
Generation 6's Evil Team is Team Flare, all dressed up in red-orange suits and wanting the world to be beautiful. However, they only want to support themselves and had a plan to destroy all life but themselves and start anew, using the Ultimate Weapon. Making Armor seems easy for this team, even though they have glasses that may or may not fit on some skins.
The Armor would be made out of a new Material, Topaz. Topaz is an orange-colored ore with a roughly oval shape. It could be obtained by smelting Topas Ore (Shaped like Rubies/Sapphires/Amethysts) and/or drops from certain Pokemon. It can also be made into Topaz Tools, Topaz Blocks (Shaped like Crystals), and of course, Flare Armor. Move tutors could use it as payment.
Opal and Skull Armor
Generation 7's main evil team is Team Skull, a street gang-like team who simply want to make enough money, sometimes earning cash in very shady ways. Another Simple one, considering that the necklace can be printed into the Chestplate and the Bandanas can be a part of the Helmet, a lot like Neo Plasma Armor.
The Second New Material, Opal, is what Team Skull's (and Rainbow Rocket's) armor is made up of. Opal is colored white but has rainbow highlights, shaped slightly flat, yet very rough. It could be obtained by smelting Opal Ore (Shaped like Crystals/Silicon) and/or drops from certain Pokemon. It can also be made into Opal Tools, Opal Blocks (Shaped like Crystals), and of course, Skull Armor and Rainbow Rocket Armor. Move tutors could use it as payment.
Rainbow Rocket Armor
Appearing in Generation 7, Team Rainbow Rocket is a revival of Team Rocket. Their intentions are to create a team of Ultra Beasts to take over every planet in their universe. Considering how similar this team is to Team Rocket, this one could be skipped, honestly. However, if the extra step is planned, then a simple edit to the Team Rocket armor could be made, with some adjustments.
The way Rainbow Rocket Armor could be made is alike to Neo Plasma Armor but is made of Amethyst and Opal instead.
Garnet and Yell Armor
For the currently final Generation, it's evil team is Team Yell. Unlike other teams, they are just fans of Marnie and want her to win the Pokemon Leauge instead. However, they can get a bit too far with what goals they plan to do. Team Yell is also easy, but the Mohawk and Paint may be a problem.
The final new material is Garnet, the ingredient for Yell Armor. Garnet is shaped like Sapphires, but have a crimson, almost burgundy color. It could be obtained by smelting Garnet Ore (Shaped like Crystals/Silicon) and/or drops from certain Pokemon. It can also be made into Garnet Tools, Garnet Blocks (Shaped like Rubies/Sapphires/Amethyst), and of course, Yell Armor. Move tutors could use it as payment.
So, what do you think of this idea? Again, the idea might have been already shared, but at least this is my own spin on this idea. I hope you enjoy this idea!