Some styling options

One thing that i’d like more control of – and maybe I already do but I just can’t figure it out correctly – is the ability to change how the button looks to reopen the message once it’s closed. I know that you include options for colors and such but here’s what I want to do:

I don’t want any button image (the arrow_up.png) at all – just text that says ‘Message’. Then I just want a simple background color added to that and no shadow. It shouldn’t be rounded just 0 radius. I’m sure I could figure out how to do it within css but I can’t seem to find the right class or id to call to do this. Any help would be appreciated.

https://ww.wp.xz.cn/plugins/wpfront-notification-bar/