Blade's kinda weird in the sense that the Riders' primary colors are represented by their undersuit and not their armor, mostly because 3 of the Blade riders just have silver armor.

The Missing Ace riders are a bit different in that they all have black undersuits, therefore their primary color would be the color of their armor, hence Glaive being gold.

Sure, but by virtue of Leangle being the only one with gold armor, I think it makes it a bit more of a special deal. Sure his main color is green, but the fact that he's also very gold can't be ignored. Especially since while silver is a neutral color, gold is not.

Though really questions of Kamen Riders' colors can get pretty arbitrary, since this isn't super sentai here...

I mean, wasn't the Leangle driver created to be evil in the first place? He's also the only one of the four who's got gold as a primary color in base form. I'm thinking he counts for the "gold is evil" pile.

The Leangle Buckle wasn't made to be evil, no. It was just made to be the strongest. Leangle was evil because the Spider Undead wasn't sealed properly (possibly because it allowed itself to get sealed, though I don't remember if they gave a specific reason why the sealing was faulty) which allowed it to influence its wearer. But regardless of reason, Leangle was still a pretty antagonistic character for much of the story, so...yeah.

Huh. I could've swore some ill intent baddies within BOARD were the ones who made the buckle. I guess I haven't seen Blade in a little while, though. :o

The belt itself was just made to be the strongest, but the Category Ace used to transform was evil.
Isaka aka Peacock Undead was the one who created the belt and he also was behind Garren sealing the Spider Undead. So technically, he made sure that the Undead wasn't properly sealed, so that whoever would use the belt was controlled by Spider and thus on the Undead's side.

I...seem to recall that the reason it wasn't sealed properly was because it threw the fight? Been a while since I've seen any Blade.

Isn't the Leangle Buckle supposed to be like the next generation driver for the Blade series

Well, yes and no. The next gen belts used in Missing Ace were designed like the Leangle buckle, but they were working with different cards. Unlike the Leangle buckle, which was designed to work with a sealed Undead, the belts used by Glaive, Larc and Lance were made to work with the Change Cerberus Rouse Card, which was an artificial card created by BOARD before the events of Missing Ace.

Spider Undead let itself be sealed on purpose because it was an ally of Isaka. Due to the fact that it let Garren win instead of being actually defeated, the seal became improper, meaning the Undead sealed still had its own conciousness and could control the host aka Mutsuki.
Mutsuki ultimately defeated Spider Undead with some help of Tarantula Undead/Shima-san and Tiger Undead/Hikaru and sealed it properly so that he could control the power of Leangle.

Don't worry, I've seen the show 3 times and still have to look some details up.

Well one thing for sure Leangle was awesome because Okamoto was the suit actor and it oozed out awesomeness head to toe.
And it farted blizzards as it kicked.
The way they added the effect made it look like it was farting shaved ice.
Sorry folks :lolol