Historically black and white NTSC had an update rate of 60Hz, when colour came along the need for a bit of delay was felt and thus the frame rate dropped to various flavours of high 59.9 Hz. We all then went digital but various cameras, workflows and whatnot were adapted for it (see also why interlacing still exists...) and thus that number stuck. A lot of video is made to it and if your screen supports it then it makes sense.
RGB and YUV then.
Basic childhood science says you can make any colour by mixing red, green and blue light. Initially colour on screens was treated much the same way, however owing to a quirk of maths you can still represent those colours by doing some calculations instead (which technically results in less storage needed and other niceties) and then you have the YUV family of colour spaces. Depending upon what is used it can be slightly lossy.
http://blogs.adobe.com/VideoRoad/2010/06/what_is_yuv.html if you want more technical.
Frankly you would probably struggle to notice either way as far as quality goes, probably also decode speed as well (and if it is just a video player then definitely) so use whatever combo you like.