Hi everybody, Ken,
colorize can be done in different ways ... (as usual in
PS....

) .. If you go for 'paint the colour in' I would advise to do it on different blank Layers set to 'Color' ... in this way you can colorize the different parts of your picture separately and increase or decrease their intensity/saturation or even change the Hues with the help of Curves, Levels, Hue&Saturation ....
What I learnt from Vikki is that skin has never one colour only, but is a mixture of different colours... (reds, yellows, magenta and cyan for caucasians, for example..) ... so, after applying the first 'coat' I usually check to see what I can do to make it less 'flat' ...
The skin in your colorizing has barely any colour in it ... that's why the 'rosy' cheeks and the hair seem oversaturated in comparison, as Caitlin pointed out ... Lips and inside of mouth have, usually, a richer/darker colour ...
I had a go at your picture .... the basic colorizing was done following this
Tutorial, corrections and enhancing were done with blank layers set to Color (as described before), Hue&Saturation and Selective Colors ...
Soleah,
great job in colorizing the skin, the only point I would do is that it is a 'one tone' colour ...