Western Star Show

Has anyone been noticing that some of the stars are changing color rapidly? They turn from blue, red, yellow, sometimes even a very pale orange. The star changes from color to color within about a half a second. It was originally only one specific star on the western horizon, but now I have been noticing many other stars showing the same characteristics. Originally I thought it was due to some refraction of the light from the star entering the western horizon and thus changing the color (much like the sun turns red when it sets) but I started to notice different stars that are in the center of the sky doing the same phenomenon. I live in Texas so I am able to see the stars fairly clearly, but I know there is someone out there that has been noticing this,