The color-coded system we use is called Chromanotes(TM), which has been made famous world-wide thanks to the popularity of Boomwhackers. Any Chromanotes(TM) product, instrument or material should be color-coded to match!
In case you were wondering, the colors are kind of arbitrary. They’re really just a rainbow-ish pattern across the instrument, nothing more.
In other words, there’s nothing inherently ‘red’ about the sound of the C note. Still, the color helps to make the abstract idea of pitch more concrete, predictable and easier to teach.