When using Bootstrap it can be challenging to change the outline colour of an input field that has focus from the user.

By default Twitter uses a blue outline that may not fit all designs.

Default Twitter Bootstrap input outline

Even adding a CSS rule for the outline does nothing.

input:focus { outline: none; }

Twitter Bootstrap input outline still unmodified

This is because Twitter Bootstrap actually adds a border and a box-shadow property to all inputs on :focus that must be overridden.

Chrome DOM inspector

So to change the outline color, just update these properties.

input:focus {
    border-color: #cfdc00;
    box-shadow: 0 0 5px rgba(207, 220, 0, 0.4);
}

Now you will see the update!

Modified Twitter Bootstrap input outline