Certified Irrigation Designer Practice Exam

Color coding helps you quickly identify what a pipe carries, and for PEX, blue is the standard color for cold water. This convention makes it easy to distinguish cold supply lines from hot ones at a glance, which reduces mistakes during installation, repairs, or upgrades. While red is typically used for hot water and white or gray may appear in some brands or installations, blue remains the most widely recognized and recommended color for cold water supply.