Age: 18-24 months

Q: When can I start to work on things like shapes and colours with my toddler?

Answer: Between the age of 18 and 24 months, your toddler will begin to sort shapes and colours. Names objects of different shapes and colours by pointing to them and try to start with a few simple ones to sort first - red, yellow, blue or triangle, circle, square.

Source: https://teachmytoddlers.com/when-to-teach-what-a-guide-for-teaching-your-toddler-colors-shapes-letters-and-more/