Dashboards are almost completely visual business intelligence tools. Therefore the visual impact and aesthetic appearance of any dashboard is one of its most important features, and careful colour choices can dramatically improve the effectiveness and clarity of any dashboard.
When you are choosing the colour scheme for your dashboard, you have two intial choices. First of all, you can choose to let the charts automatically adapt a particular colour scheme. However this will usually mean that each chart will be individually coloured and that the overall dashboard will not display a uniform appearance. Alternatively you can choose to your colours meaningfully, to highlight various aspects of your data. For example in a KPI dashboard you could use the colour red to render data points that fall below a certain threshold, thereby highlighting areas that are underperforming. Many charts use colours as the means through which they display their data, e.g. 'heat' and thermometer graphs.
When you are choosing the colour scheme of your graph, you should ensure that the background colour of each chart is chosen so as to throw the data points and plots into sharp relief. Another thing to bear in mind is that reusing certain colours automatically links those areas in the minds of the viewers. Therefore if you use the same background colour for related charts, it will be immediately apparent to users of the dashboard that those items are connected.
It is also a good idea to make sure that all non-data related items, such as structural elements, are in neutral colours that will not draw attention away from the main chart. Ignoring this rule will lead to dashboards that are cluttered and confusing.