Colors are one of the first things that parents think about teaching their children. Teaching your preschooler colors can be a lot of fun.
You should wait to introduce colors until your child has a solid vocabulary of nouns. A preschooler's brain is wired to learn the names of objects before learning to describe those objects. Kids have what is called the "language explosion" between 18 and 24 months of age, during which they will be learning lots and lots of nouns. Work with their brains during this time by naming everything, and by not confusing things by adding adjectives.
After about the age of two, your child may be getting ready to learn colors. The best way to kick off this process is by having a "red day." (Really, it can be any color you want.) Pick a color, like red, and focus on it. Have everyone wear red. Pick red foods to eat. Pull out red blocks or red toys. Finger paint with red paint. Put up red streamers and balloons and hang red tissue paper over the window. Get as much red in your day as you can. Every time you see something red, point it out.
After a day saturated in red, your child will be grasping the concept of redness. For the rest of the week, every time you see red, point it out. You can ask, "Do you see anything red in this room?" Find red together in picture books or in the grocery store. Don't introduce a second color yet—focus on red for the whole week.
The following week, repeat the process with a second color. After this second week, you can play games with the two colors. "Race for the Colors" is a great game for reinforcing color skills. You can also save jar or bottle lids of the two colors. Let the child sort them into groups of the same color. If you have two lids of each color, you can put each lid under a cup or bowl. Have them pick up one cup at a time and try to find matching lids.
Don't make practicing colors a test; keep it a game. Your child will learn colors through lots of repetition and playing with the colors. Have fun with it!