Thank you! Gave me a start to trying my own, I’ve combined your suggestion with the HabPanel widget help file here and came up with the below if anyone wants to copy. Thanks for the headstart!
<div ng-if="itemValue(config.wemosensor)=='OFF'">
<button class="btn btn-med" style="background: red; color: white"
ng-click="sendCmd(config.wemoswitch, 'ON')">
{{config.name}}
</button>
</div>
<div ng-if="itemValue(config.wemosensor)=='ON'">
<button class="btn btn-med" style="background: green; color: black"
ng-click="sendCmd(config.wemoswitch, 'ON')">
{{config.name}}
</button>
</div>```