This assumes that you are running Bukkit: You go and install the SimpleColors plugin that you find from the bukkit plugin list (plugins.bukkit.org).
you have to be the server owner to change it.
You can't unless you have a mod, hacking into Minecraft, or have a texture pack.
You can't. The color of a cauldron is gray and it will stay gray.
To change the color of a wolf's collar, right click on the collar with a dye in your hand.
You can't rank up on a Minecraft server because there are no ranks unless the host of the server has a rank plugin.
Do not think so.
You can't.
You can't unless you get a mod, you hack or you get a texture pack
The only color of a pig in minecraft is pink.
An admin is a administrator of a Minecraft Server. They are of a higher rank than Moderators.
t changes depending in what die you put into the star when you made it
ask the host to rank you up