Change icon-bar (☰) color in bootstrap

Try over-riding CSS using !important

like this

.icon-bar {
   background-color:#FF0000 !important;
}

The reason your CSS isn't working is because of specificity. The Bootstrap selector has a higher specificity than yours, so your style is completely ignored.

Bootstrap styles this with the selector: .navbar-default .navbar-toggle .icon-bar. This selector has a B specificity value of 3, whereas yours only has a B specificity value of 1.

Therefore, to override this, simply use the same selector in your CSS (assuming your CSS is included after Bootstrap's):

.navbar-default .navbar-toggle .icon-bar {
    background-color: black;
}