The following potions have the corresponding effects:
POTION - EFFECT Yellow - Switches your Sim's traits around. For example, if at 10 nice, after drinking it will be 0 nice. Red - Love potion, works randomly on anyone of the opposite gender. Blue - Refreshes almost all feelings, hunger, comfort, etc. Purple - Turns the Sim into a monster that walks around your house breaking everything. Turns back when there is nothing to break. Green - Does the opposite of Blue (makes you sad, weak, hungry, etc.) Orange - Makes your Sim invisible; becomes see-through and half of his or her legs disappear. Dark Green - Creates a Clone.