change colors using css

[nathgit]

What are the different selectors for changing color in buttons? I have a button with the btnRed class, & I created a CSS script to change the background & text color, & a few other things
.btnRed{
background-color:#ff0000 ! important;
color:#ffffff !important;
font-weight: bold !important;
text-decoration:underline ! important;
}

This makes the line behind the button red, but not the background of the button itself. The other code doesn't work either.