What is the Difference between RGB Color and CMYK Color?

RGB is red/green/blue, the colors of light a monitor uses and mixes together to make various colors on screen. 

CMYK is Cyan, Magenta, Yellow, Black, the various ink colors a printer mixes together to make colors on printed material. 

Make them in CMYK. It will still look different on screen than it does on paper, but it will be closer. 
The difference is, one is creating color using light, one is creating color using the reflection of light off pigmentation.