You are almost certainly seeing a JPEG preview file. Even if you only save RAW files, the vast majority of cameras generate a preview or thumbnail JPEG and that is what you see on the LCD on the back of your camera.

RAW files contain monochromatic luminance values for each photosite. Since the sensor is masked with a pattern of filters that allow different colors of light to pass through adjacent pixel wells (usually Red, Green, and Blue), there is no color information until the RAW data is demosaiced so that an R, G, and B value can be interpolated for each pixel.

With most cameras if you only save to JPEG what you see on the rear LCD is also a smaller thumbnail preview of the full JPEG. Most cameras have sensors with much higher resolution than the LCD on the back of the camera.