You may want to associate specific KPIs with particular colours, or simply implement a colour scheme to match you, or your client's, branding.

If you have multiple series in your chart you can set the colour of each of these through the report's visualisation panel.

Please note that if your report is a single metric, split by a particular dimension from your data - eg. device type - then colours in your chart are determined by the colours assigned to the individual value for that dimension. To change dimension colours please see this help article.

To change the colour of metrics within reports, either open the Report builder or the Visualisation menu. Locate the metric you would like to update. Select 'Plot Colour', users can select the colour they would like.