Color Hack decks manipulate colors and color-related rules text to change how cards interact. This can mean making a spell or permanent a different color, replacing one color word with another, or even rewriting basic land types to alter color-sensitive effects.
Sleight of Mind can rewrite every instance of one color word on a spell or permanent, while Magical Hack performs a similar trick with basic land types instead. Blind Seer approaches the idea from another angle by directly changing the color of spells and permanents, making protection, hosers, and other color-specific cards much easier to manipulate.