Colours are important if we didn't have colours every thing would look boring.
There are many different colours you can even make lots of colour using red, blue and yellow
You can get a colour wheel and make all the different colours, Maybe I can show you the different colours.
The Primary colours are the most important colours of all colours.
The 3 Primary colours are blue, red and yellow without those colours there would be no colours.
With those 3 colours you could make all the colours like secondary colours and tertiary colours.
The secondary colours are created from the primary colour the primary colours a mixed to make green, orange and purple. To create green you need to mix yellow and blue = green.
If you want to create orange you will need to add red and yellow = orange. The last colour secondary colour is purple you just need to add blue and red= purple.
After the secondary colours you got the Tertiary colours there are lots of Tertiary colours.
The tertiary colours are just called red-violet, red-orange, yellow-orange, yellow-green, blue-green, blue-violet, and they are the tertiary colours.
Im now finish and you can now know how to make all the different colours by just using yellow, red and blue. If you know how to make all the colours you can maybe teach someone else