can't the way to change the bkcolor of buttonIcon

which class ?
.webic_img_btn ?

Yep, and also focus/hover/active selectors to expand the styling:

http://webix.com/snippet/c6f1d668

Doesn’t work for me with type = iconButton
http://webix.com/snippet/8ba62578

The classname for icon buttons is webix_img_btn_abs.

http://webix.com/snippet/7f759b3d

So gooood