Definitions for "Color Up"
Exchanging low denomination chips for high. This reduces the pile you have to carry, keeps the table supplied with plenty of chips, and allows the house to ascertain how you did. Commonly done when players leave a table.
During a poker tournament or cash game, the house may elect to remove the smaller denomination chips from play. Usually a "color up" will result in removing those big stacks of chips from players and replacing them with a smaller quantity of higher denomination chips.
To exchange cheques for higher denominations. Used as a synonym for "color out," except that a player may "color up" and continue playing.