It's a completely different product, targeted to a different customer base, folks who have no interest in installing the individual apps or theme modification software, just load-n-go. The themes themselves are copyrighted & used by permission of the organizations they represent.
MyColors was never intended to duplicate the functions of ThemeManager. As I understand it, the individual WB skins that are part of MyColors themes install to the normal WB folder and can be used by WB (if WB is installed separately) without using other components of the theme (you could use different cursors, for instance) but the MyColors WB themes themselves are not modifiable the way other WB skins are (since they are copyrighted & encrypted). So, in that sense, if you have the relevant OD apps installed, you can still mix & match; use a different wallpaper, for instance, or a different IP theme. You cannot do that from within the MyColors application itself, however, which is designed in a way that permits folks without ODNT or individual OD apps to use them, no fuss no muss.
Hope that helps.