Use higher specificity to stop your changes affecting other areas.
For the member card for example add .xenOverlay.memberCard before those classes:
Code:
.xenOverlay.memberCard .pairs dt, .pairsInline dt, .pairsRows dt,
.xenOverlay.memberCard .pairsColumns dt, .pairsJustified dt {
color: #0A2A5A !important;
}
Do the same for the other areas and it won't afffect everything which uses those classes.