Colors That Talk: Red, Yellow, and Green
Look at a traffic light. It never says a word, but every driver and walker knows exactly what to do. Red means stop. Yellow means slow down. Green means go. That is a sign talking to you without any words at all!
What You'll Learn
- What a sign is and how it sends a message - Why red, yellow, and green were chosen for traffic lights - How to read three common street signs - Why signs need to look the same everywhere
A Sign Is a Little Message
A sign is something you see that tells you something without using sentences. A stop sign is shaped like an octagon (eight sides) and colored bright red. You do not need to read the word 'STOP' to know to stop — the shape and color already tell you.
Why Red, Yellow, and Green?
Long ago, train companies picked red for danger because red is easy to see far away, even in fog. Green was chosen for safe to go. Yellow sits in between as a warning color. When cities built the first traffic lights in the early 1900s, they borrowed these same three colors from trains.
The first electric traffic light was put up in Cleveland, Ohio, in 1914. It only had red and green lights — yellow was added a few years later!
Signs You See Every Day
A crosswalk sign with a walking person means it is safe to cross. A hand means stop and wait. A yellow diamond sign with a curvy arrow warns of a curve ahead. Each shape and color is a clue that helps you stay safe without reading a single letter.
Match each sign color to what it means.
Terms
Definitions
Drag terms onto their definitions, or click a term then click a definition to match.
Why is a stop sign shaped like an octagon instead of a circle or square?
On your next walk or car ride, count how many signs you see that use color or shape instead of words. You will be surprised how many there are!
What color did traffic lights borrow their meaning from?
Design Your Own Sign
Draw a sign for your bedroom door using only a shape and a color — no words allowed. For example, a red circle could mean 'Do Not Enter' and a green square could mean 'Come In.' Show it to a family member and see if they can guess what it means without you explaining.
Flashcards — click each card to reveal the answer
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