Use the \color{nameColor} code from LATEX inside $$$$, now that github can support:

$${\color{red}Red}$$	
$${\color{green}Green}$$	
$${\color{lightgreen}Light \space Green}$$	
$${\color{blue}Blue}$$	
$${\color{lightblue}Light \space Blue}$$	
$${\color{black}Black}$$	
$${\color{white}White}$$	
$${\color{yellow}Yellow}$$	
$${\color{orange}Orange}$$

like this too:

$${\color{red}Welcome \space \color{lightblue}To \space \color{lightgreen}Github}$$

$${\color{red}Welcome \space \color{lightblue}To \space \color{lightgreen}{github}}$$