The most common color of warning signs is:
- Red.
- Yellow. ✓
- Green.
- Blue.
Answer: B. Yellow.
Yellow is the most common color used for warning signs.
Why this is the answer
The handbook's standard colors table lists yellow as the color for general warning or caution. That means a warning sign is normally yellow because the color itself tells you to use caution. Red is tied to stop, yield, or doing what is posted on the sign, green to permitted movements and direction guidance, and blue to motorist services guidance. None of those descriptions covers general warnings.
Why the other answers are wrong
- A. Red. — Red marks stop, yield, or doing what is posted on the sign, not general warning.
- C. Green. — Green shows permitted movements or direction guidance, not warnings.
- D. Blue. — Blue points to motorist services guidance, not general warning.
Remember it
When you see yellow, think caution: it is the color the handbook assigns to general warnings.
Official handbook: Texas Driver Handbook (DL-7), Chapter 5: Signals, Signs, and Markers , p. 26