"Create" new blog entry button: text color should be same as for "Add" button

Easy to see with the "Garden" Theme:
The "Create" button in the blog home page has the same background color as the "Add" button, but the same font color as the "primary" bttons.

That is ok for the specific "Garden" theme, but causes trouble for themes where users e.g. select a very bright green background and blakc font color for the add button - because the "Create" button uses "white" as font color, the text becomes nearly unreadable.

The problem is caused by a CSS class 'button' - which is used for colibri.
I am not sure if it is ok to drop that one, however - or if there is a better option.