Bar styling options

New Ionic user here, and loving it.

I would like to suggest that it would be helpful to have some additional classes for styling header and footer bars similar to the way buttons are styled. In particular it would be nice to invert the the colors of a header bar (i.e. bar with a white background and colored text).

for example, something like this:

< ion-nav-bar align-title="center" class="bar bar-header bar-calm">  

(calm color background, white text)

 <ion-nav-bar align-title="center" class="bar bar-header bar-calm bar-clear"> 

(white background, calm color text)

I know this can be easily accomplished with custom css but it seems like something that would be handy to have out of the box, especially since buttons work the same way