Another possible way to have bootstrap icons in a different color is to create a new .png in the desired color, (eg. magenta) and save it as /path-to-bootstrap-css/img/glyphicons-halflings-magenta.png
In your variables.less find
// Sprite icons path
// -------------------------
@iconSpritePath: "../img/glyphicons-halflings.png";
@iconWhiteSpritePath: "../img/glyphicons-halflings-white.png";
and add this line
@iconMagentaSpritePath: "../img/glyphicons-halflings-magenta.png";
In your sprites.less add
/* Magenta icons with optional class, or on hover/active states of certain elements */
.icon-magenta,
.nav-pills > .active > a > [class^="icon-"],
.nav-pills > .active > a > [class*=" icon-"],
.nav-list > .active > a > [class^="icon-"],
.nav-list > .active > a > [class*=" icon-"],
.navbar-inverse .nav > .active > a > [class^="icon-"],
.navbar-inverse .nav > .active > a > [class*=" icon-"],
.dropdown-menu > li > a:hover > [class^="icon-"],
.dropdown-menu > li > a:hover > [class*=" icon-"],
.dropdown-menu > .active > a > [class^="icon-"],
.dropdown-menu > .active > a > [class*=" icon-"],
.dropdown-submenu:hover > a > [class^="icon-"],
.dropdown-submenu:hover > a > [class*=" icon-"] {
background-image: url("@{iconMagentaSpritePath}");
}
And use it like this:
<i class='icon-chevron-down icon-magenta'></i>
Hope it helps someone.