So in Smallville, and I'm not quite sure where else this was mentioned, there are Kryptonites that have colours other than green. Just as a brief note about the different Kryptonites, there are Green, Red, Blue, Gold, Silver, Black, Gemstone, and Clear. The first four are natural where as the last four are synthetic.
Green Kryptonite: The one that we all known. It is like poison for Kryptonians. It weakens any Kryptonians near the stone and will slowly cause the Kryptonian to die. It basically makes them human if the stone is small enough and does not impact many of their abilities (Shown in the animated movie Justice League: Doom). It also has side effects on humans as well.
Red Kryptonite: The "evil" Kryptonite. It brings out the Kryptonians immoral personalities and causes them to think only of themselves.
Blue Kryptonite: It strips the Kryptonians of their powers but does not poison them. Its effect only works in close proximity of the Kryptonian.
Gold Kryptonite: It is like the blue Kryptonians but permanent.
Silver Kryptonite: It is the Kryptonite created by Brainiac. It induces paranoia in Kryptonians. It will make Kryptonians' fear seem real and hallucinate.
Black Kryptonite: Created through heating green Kryptonites. It can separate or combine the moral and immoral halves of a Kryptonian. (Probably wouldn't combine two immoral halves of two different Kryptonians.)
Gemstone Kryptonite: Mined from quarries from Smallville. It can temporary grant some of the superpowers of a Kryptonian.
Clear Kryptonite: Neutralized green Kryptonites. Basically has no effect on Kryptonians whatsoever but it still came from Krypton.
Now that the "refresher course" is over, now comes my hypothesis. What if there are some other types of Kryptonites that are not yet discovered, or revealed.
For example, what if the Kryptonians also have a Viagra like stone? Like a White Kryptonite. It makes the Kryptonians near the stone sexually active and driven by sexual desires. It would be a useful Kryptonite for Lois to possess if she ever feel neglected.
What if there are some "hippie" Kryptonians as well? Like a Pink Kryptonite. It makes the Kryptonians near the stone lose their will to fight. Imagine Lex Luthor using this Kryptonite when he fights Superman. Superman would be more like Ghandi than the super soldier.
How about a Kryptonite that can hypnotize a Kryptonian? Like a Spiral Kryptonite. I know that Lex tried, through different ways, to control Superman, but it would be easier for him just to possess such a stone instead of all that trouble.
Lastly, what if there is a Kryptonite that reverses their powers? Like a reflective Kryptonite. It might not affect Superman's heat vision and ice breath since he can just switch the two, but it would be a great hindrance if his super speed became slow-mo speed. Faster than a speeding bullet? More like slow as molasses.
Anyways, this is just some of whimsical thinking about the Superman's world. If you have any comments, suggestions, or just like this note, please let me know.