Cell health and viability: Improve emphasis of cell lines titles

components/report_cards/chemical_probe/CellViabilityAndHealthComponents/CellPropertiesPlots.vue

@@ -2,7 +2,7 @@
   <div>
     <template v-for="cellData in cellViabilityData">
       <div :key="`${cellData.cellLine.name}-title`">
-        <v-banner single-line>
+        <v-banner single-line color="blue-grey lighten-4">
           <div class="primary--text font-weight-bold">
             {{ cellData.cellLine.name }}
           </div>