I know that there are lots of ways to teach the colors but the following technique has worked really well for me over the past few years and I thought that I would share it. I'm sure that I didn't invent the wheel here, but it is something that just developed rather than my reading about it somewhere.
I teach the colors on Kindergarten Day over a period of a few weeks using books. Any series of simple children's books that emphasize color will do, but my favorite is the series from Alan Rogers: Red Rhinoceros, Yellow Hippo, Green Bear, and Blue Turtle (I don't know if those are the real titles or not, I just translated them from the Spanish).
Each Friday for the first four weeks I read these books. I generally DO NOT read the text in these books (these are level-1 students after all), but I start to describe the pictures. I start off with saying there's a rhinoceros and then I say that he's red. I then ask the students if he's red or some other color that's on the page. When I say red, I point to the red with my laser pointer and when I say the other color, I point to that color on the page. The kids, of course, say red. I then talk about his nose (really his horns, but we're limiting vocab here). I say are they red or yellow, again pointing to each color as I mention it. In the book they are yellow, so they kids respond with yellow. I then go back and circle, compare and contrast the rhino with his nose. I add other colors that are exampled on the page for contrasting and comparing. I'll talk about the eyes and ears and their size and how many there are (simple way to get in some opposite adjectives and the lower numbers). I then will point out another high-frequency noun on the page and we'll talk about it and it's color. Is it big or small? Is it bigger or smaller than the rhino? Does the rhino have big or small eyes? Two or four eyes? Big or small ears? One or two ears? Is the rhino fat or skinny? etc. I continue to circle everything and every color on the page and then I move on to the next.
One thing that really makes this great is that I scan the pictures into powerpoint so I can project the book on the screen and make it very large for the students to see. I also read with much enthusiasm as if the kids are just babies. They get a real kick out of it and I have their attention for the whole time.
It takes me about 30 minutes or so to get through one of these books this way and by the end of the four weeks, they know their colors, some basic descriptive adjectives, the names of these animals, and some other high-frequency nouns that show up in the books. I can't remember in which one of the books it is, but one also has a lot of shapes in it and we can talk about the basic shapes in the target language as well.
Of all the different ways that I have taught the colors, I have found this to be the most successful and the one that stays in long-term memory the longest. Plus it's fun for the kids and if you add apple juice and animal crackers to kindergarten day (Vielen Dank! Janet in IN), you've got an engaging lesson for the kids that's sure to be a hit!
Please leave your ideas and comments below! :)