Make "Send with" button selection more visible

The buttons at the bottom allow the user choose which accounts to "Send with" when posting an update.
The current selection is shown by a change in the button shading.
The difference between selected and unselected accounts should be more visible.
Given many accounts with different colors and logos, the shading difference is too difficult to see, for such an important option.
This could be done with large checkmarks, or with more intense color changes.