Which color corresponds to sprinkler heads rated 135° to 170°F?

• A. White
• B. Blue
• C. Red
• D. Uncolored or Black

Answer: (D)

Sprinkler heads use color coding to show their temperature rating, so you can quickly confirm the head will actuate at the intended heat level. For the 135° to 170°F range, the heads are uncolored (no color) or black, which is how this rating is identified on many systems. This simple color cue lets you verify in the field that the correct head is installed for the expected fire temperature. If a head shows a different color, it signals a different rated temperature, which could affect how the system responds in a fire. The key idea is that the color (or lack of color) communicates the operating temperature at which the head will release water.