If a sprinkler is color coded White, what color bulb does it use?

• A. Orange/Red
• B. Blue
• C. Purple
• D. Yellow/Green

Answer: (D)

Color coding on sprinkler heads is used to identify the activation temperature at a glance. The glass bulb inside the head has a color that indicates its rated temperature, and manufacturers pair certain body colors with specific bulb colors. For a sprinkler body coded white, the standard pairing is a yellow/green bulb. So, when you see a white-coded sprinkler, expect the bulb to be yellow or green. This quick visual cue helps firefighters assess the protection level and likely activation temperature without needing to measure anything.