Green:Green Kryptonite is the most common form and makes kryptonian's feel dizzy,nauses,in pain and in long enough exposure can render them unconsious and possibly kill them.This can be avioded with lead.When being exposed to green K the kryptonian's invulnerability is by passed.
Red:Red Kryptonite is a bit rarer than green but can still be found.Red Kryptonite strips a kryptonian of his inhibitons and social consience making their deepest desire's come to the surface,so they act on their emotions.Red kryptonite basically brings out their "Primal Instincts".In the TV series Clark has a split personality while under Red K,Kal short for his birth name Kal-El.According to Clark Kal "does things [Clark] doesn't want to do".
Blue:Blue Kryptonite removes a Kryptonian's powers when they come in proximity or contact,the removal of the powers is not painfull.
Gold:Gold Kryptonite is perhaps the most dangerous kryptonite,It can strip a kryptonian of their powers permanently.Gold K probably blocks the absorbal of solar energy making them lose their powers,It also leaves permanent scars.
Black:Black Kryptonite is can split a being into two sides good and bad(if it is a human) and human and Kryptonian(if it is a kryptonian) the two beings can be brought together into one again when exposed the second time.
Gemstone/Jewel:Gemstone Kryptonite is harmless to Kryptonian,but grants them aditional powers.The power is mind control,a person does anything the kryptonian says(Literally) this doesn't affect other Kryptonians.
Jewel:Jewel Kryptonite is the comic version of Gemstone Kryptonite Jewel Kryptonite possesses the ability to amplify the psychic powers of people in the Phantom Zone.
Silver:Silver Kryptonite causes paranoia and dellusions without the loss of physical capability.
Clear:Clear Kryptonite is green k neutralized and has absolutly no effect on Kryptonians.