The structure of the tooltip is described in the docs. To change the style you need to override tooltip-inner
and :arrow
Update for Bootstrap 4.0.0
.tooltip-inner {
background-color: #00cc00;
}
.tooltip.bs-tooltip-right .arrow:before {
border-right-color: #00cc00 !important;
}
.tooltip.bs-tooltip-left .arrow:before {
border-left-color: #00cc00 !important;
}
.tooltip.bs-tooltip-bottom .arrow:before {
border-bottom-color: #00cc00 !important;
}
.tooltip.bs-tooltip-top .arrow:before {
border-top-color: #00cc00 !important;
}
(where #00cc00
is the desired tooltip color)