ARE YOU GUYS NUTS ???
Why the fudge has nobody mentioned Fluorite ?
It's actually known as " the most colourful stone in the world "
You can get all sorts of bright vibrant colours with fluorite and sometimes even multiple colours.
Also Labradorite is very beautiful and colourful and has a certain " depth " to it that is hard to explain unless you see it in person.
And of course quartz is awesome, amythest is actually a type of quartz, and so is citrine.