A friend gave me a fabulous indoor activity idea that your child will cherish for a lifetime.
To teach your baby about colors, dress her up in all red, all orange, all blue... you get the idea, all of the colors of the rainbow. Take her picture in each color, perhaps surrounded by household objects of the same hue. (apples, oranges, pears, plants, toys, rugs)
Upload the images to your computer and type the color across the top of the page. Take your pages to Kinko's and have them laminated into a keepsake book that your baby may even share with her own child someday.