Update index.d.ts
Update index.d.ts

ChartColor should be of type String[] too
nycdotnet/DefinitelyTyped,rolandzwaga/DefinitelyTyped,alexdresko/DefinitelyTyped,isman-usoh/DefinitelyTyped,chrootsu/DefinitelyTyped,arusakov/DefinitelyTyped,AgentME/DefinitelyTyped,alexdresko/DefinitelyTyped,georgemarshall/DefinitelyTyped,AbraaoAlves/DefinitelyTyped,AbraaoAlves/DefinitelyTyped,zuzusik/DefinitelyTyped,abbasmhd/DefinitelyTyped,dsebastien/DefinitelyTyped,zuzusik/DefinitelyTyped,ashwinr/DefinitelyTyped,magny/DefinitelyTyped,georgemarshall/DefinitelyTyped,QuatroCode/DefinitelyTyped,georgemarshall/DefinitelyTyped,jimthedev/DefinitelyTyped,zuzusik/DefinitelyTyped,ashwinr/DefinitelyTyped,markogresak/DefinitelyTyped,georgemarshall/DefinitelyTyped,aciccarello/DefinitelyTyped,arusakov/DefinitelyTyped,aciccarello/DefinitelyTyped,nycdotnet/DefinitelyTyped,benishouga/DefinitelyTyped,one-pieces/DefinitelyTyped,QuatroCode/DefinitelyTyped,AgentME/DefinitelyTyped,arusakov/DefinitelyTyped,benishouga/DefinitelyTyped,jimthedev/DefinitelyTyped,laurentiustamate94/DefinitelyTyped,abbasmhd/DefinitelyTyped,AgentME/DefinitelyTyped,aciccarello/DefinitelyTyped,borisyankov/DefinitelyTyped,AgentME/DefinitelyTyped,borisyankov/DefinitelyTyped,magny/DefinitelyTyped,amir-arad/DefinitelyTyped,benliddicott/DefinitelyTyped,benishouga/DefinitelyTyped,rolandzwaga/DefinitelyTyped,dsebastien/DefinitelyTyped,minodisk/DefinitelyTyped,AbraaoAlves/DefinitelyTyped,mcliment/DefinitelyTyped,chrootsu/DefinitelyTyped,isman-usoh/DefinitelyTyped,minodisk/DefinitelyTyped,jimthedev/DefinitelyTyped