Search your library for a white card, a blue card, a black card, a red card, and a green card. Reveal those cards, put them into your hand, then shuffle.
"It's self-indulgent, I admit, but I do like to watch my own symphony play itself out."
—Nicol Bolas
You may find multicolored cards with Conflux. The white card you find, for example, can be any number of colors, as long as white is one of them. What colors it is won't impact what other cards you can find. For example, you may find a white-blue card as the white card and another white-blue card as the blue card.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.