4 Colors is a turn-based discard or shedding card game similar to Uno. The player who discards all the cards in their hand wins a round. To win the game, they must win enough rounds to earn a total of 250 points before their AI opponents in two-person, three-person or four-person play. They earn points based on the sum of the numbers on the cards left in the hands of their opponent or opponents at the end of a winning round.
The game places a draw pile and a single face-up card between the players. Each player receives seven cards. They must discard by matching the color or number of the face-up card. If they don't have a matching card in their hand, they must draw a new card to add to their hand or discard.
4 Colors ramps up the excitement and complexity of the game by providing several tricky special cards designed to make each round last longer. Three of these cards have a 20-point value. The Action card, a hand holding two cards, forces the next player to draw two cards from the pile and give up their turn. The Skip card displays a prohibition circle with a diagonal line through it and takes away the next player's turn. The Reverse card, two curved circles, allows the player to switch the direction of the turns to bypass a player with fewer cards.
The four-color diamond Wild Card (50 points) allows a player to change the color of the next turn. The Wild Draw Three (50 points) allows a player to change the color and forces the next player to draw three cards.
Lastly, when the player discards all but one card, they must press a diamond-shaped 1 button or receive a two-card penalty.