Turns out all you have to do is remove “Watts”. It works perfectly again.
backgroundColors:[ [value: "0", color: "#153591"], [value: "500", color: "#1e9cbb"], [value: "1000", color: "#90d2a7"], [value: "1500", color: "#44b621"], [value: "2000", color: "#f1d801"], [value: "2500", color: "#d04e00"], [value: "3000", color: "#bc2323"], [value: "6000", color: "#90d2a7"], [value: "9000", color: "#44b621"], [value: "12000", color: "#f1d801"], [value: "15000", color: "#d04e00"], [value: "18000", color: "#bc2323"] ]