I don’t think ‘crept’ is the correct word. Aside from Red K (which was introduced twice, with two different origins*), all the variants were reintroduced wholesale in a brief story in one of the annuals, then gold got actual use in the New Krypton arc.
Is there a fuchsia kryptonite? Magenta? Teal?
Only in San Francisco.
Anyway, there are numerous stories from the fifties in which Superman loses his powers and finds that kryptonite becomes harmless to him as a result. They always irritated me (along with stories of Superman’s powers being “passed on” to another person through various means) but I guess with a perfect invulnerable character, the writers had trouble coming up with challenges, and since Superman’s powers weren’t firmly grounded in anything remotely approaching a scientific basis, why not treat them like a magic spell, with magic-spell-rules?
If I recall correctly, Pink Kryptonite was introduced as a one-panel gag in Peter David’s Supergirl run. She was in an alternate Silver Age, and its effect was to make Superman fabulous! ( I recall him giving fashion tips to Jimmy Olsen …)
Yes, Wikipedia has a list actually.
Amusingly I have come across Supergirl porn involving magenta kryptonite…three guesses as to the effect it has.
Link or it didn’t happen. 
I fear something involving Charles Gray and Susan Sarandon.
To the porn, or to Der Trihs “coming across” it?
The first, most definitely!!!
No link, since I don’t want to make the mods mad. I did find it though; if you are genuinely curious, it’s at hentai-foundry.com, artist by the name of Ganassa. A series of several pictures that turns out to be titled Purple Trouble (although it still looks magenta to me). I also discovered in the process that someone named skottichan has a pic involving pink kryptonite and a lesbian scene.
Then you are just about to be out-nerded!
I was sure I recalled Gold Kandorite from a late-60’s Lois Lane. It may have simply been called Kandorite as this party seems very sure of.
Oh, and about the Blue K-- the precursor was a green glowing substance called “his Kryptonite” by Superboy. It was formed after Professor Dalton’s imperfect duplicating machine exploded, in parallel to Krypton exploding and forming “my” Kryptonite. It created the initial illusion that Superboy’s imperfect duplicate was not capable of consciousness or movement. The professor assured Superboy that it was made of “non-living” matter. After the debris was cleared away Superboy spotted the creation walking about and talking in a “mumbling” way. Superboy eventually decided that the well-meaning being (which he likened to a walking, talking computer) was too dangerous to be allowed to exist, but conventional weapons failed miserably. (The one thing that wasn’t imperfect about the original Bizarro was its powers. Go figure.) When he finally deduced that the glowing, green remnants of the explosion caused an initial paralysis, he rather cold-bloodedly announced to it that he was going to destroy it with a super-force collision holding a plate of it, and insisted that it not resist. Bizarro was completely cooperative and sure enough the creature was completely disintegrated by the collision.
In the wake of the destruction a completely blind girl who had befriended him (Does that remind you of an early horror novel?) was completely cured by the falling dust. Since Bizarro was so completely cooperative in this destruction (up to flying defiantly at the shield Superboy was holding, a move that may have seemed defiant) he could only wonder whether the creation knew what would happen and intended it. This would seem to go against the idea of it being without a “soul.” Then again, when a disguised adult Luthor recreated an adult Bizarro-Superman, its reaction was to attack Luthor in a rage for “bringing him back” rather than Superman, as Luthor planned.
I know that Smallville had some old Kryptonian rituals that involved Kryptonite, so, in that universe at least, it must’ve been available on Krypton (likely in limited amounts) pre-explosion. The fact that actual Kryptonians were using it probably indicates that it wasn’t quite as toxic as it is on Earth, but the fact that it was a ritual sacrifice implies that it did have some effect.