Define a color for \title, \address and \phone commands of a CV

The colors of moderncv are controlled by color0, color1 and color2 (the last one being used for the elements you mention). You can redefine these as you like (example for cyan):

\definecolor{color2}{RGB}{0,255,255}

Some predefined settings can be loaded through \moderncvcolor:

\moderncvcolor{blue}

where the argument can be blue, orange, green, red, purple, grey or black.

Finally, you could also use directly \textcolor in the argument of any moderncv command other than \email:

\phone{\textcolor{red}{123 456 7890}}