Go to : admin => customize => theme => edit HTML et CSS => tab CSS => open "custom.css" and add :
.ipsTags a[href*="/tags/microsoft/"],
a.ipsTag_prefix[href*="/tags/microsoft/"] {
background: SeaGreen !important;
}
html[dir="ltr"] .ipsTags a[href*="/tags/microsoft/"]:before,
html[dir="ltr"] a.ipsTag_prefix[href*="/tags/microsoft/"]:before {
border-color: transparent Seagreen transparent transparent !important;
}
Change"microsoft"by one other tags existing in yoru board
Change"SeaGreen"by one another color or hexa code (#xxxxxx) for change color
Rsults :