Start out by introducing colors one by one to the child. Start with colors that are easy to pronounce, such as red, blue and green. Pick out items from around the house and group them by color on the table.
Print out worksheets with colored shapes on them, or use colored construction paper to cut the shapes out. Cookie cutters are great for tracing out shapes. Start out with simple, easy-to-identify shapes like squares or a circles. You can introduce shapes while teaching colors, but it is a good idea that the child be able to clearly identify either shapes or colors, before introducing the other one.
Use worksheets to practice learning shapes and colors. Children learn through repetition and practice. Make sure to show the child the difference between an oval and a circle and a square and a rectangle. Print out a coloring page with shapes on it. Have the child color the shapes different colors. Ask, for example, "Can you find the circle? Can you color the circle blue?"
Use books, such as "Color Dance" by Ann Jonas, to teach children about colors. See if the child can point out colors on his or her own. (It is normal for a child to pick one color and call everything that color while he or she is still learning.) There are also books for teaching children about shapes, such as "My Very First Book of Shapes" by Eric Carle.
Make a game out of learning colors and shapes. Play "I spy" or a memory match game with shapes and colors. When a child has mastered a color or shape, make sure you praise him or her. Make the child repeat the color or shape.
Get out the art supplies. Choose fingerpaints with a variety of colors. Paint shapes with the child, and comment on the colors you both use. Make faces out of shapes. Ask the child what colors or shapes he or she sees in your drawing. Play a game to see who can come up with the most shapes and colors.