Component and RGB are not the same, even though the coloring of the plugs appears the same.

Component is a subtractive format. Meaning you start with the original signal, then break it down into a seperate luminance signal(green) and then two seperate chrominance signals minus red and blue respectively. The process, although not carrying a green chrominance signal allows green to be interpolated because whatever is left over after you subtract red and blue has to be green.

RGB is the full luminance signal sent with the full chrominance signal for each respective color channel(i.e. full blue channel with full chrominance).

RGB is more accurate because it is a higher bandwidth transmission, but component video is considered a lossless process, because although you can detect loss with a meter, what is lost with the signal is not visible to the human eye. Component is used because it saves bandwidth.