The color of  view bar can be changed from wpresidence\js\property.js

 

 

You need to add backgroundColor like this

datasets: [
{
label: wpestate_property_vars.property_views,
backgroundColor:”rgba(228,190,110,1)”,
fillColor: “rgba(220,220,220,0.5)”,
strokeColor: “rgba(220,220,220,0.8)”,
highlightFill: “rgba(220,220,220,0.75)”,
highlightStroke: “rgba(220,220,220,1)”,
data: traffic_data
},
]