Hi Richard Turner,
Changing the contrast could be done with changing the theme at runtime. You can implement this functionality in Sitefinity. You can use QueryStrings and RadComboBox control to append a QueryString from the client side using
event of the RadComboBox control. Then inside InternlaPage class there is a method
which you can override, read the QueryString value and set the theme
the Telerik team
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Public Issue Tracking
system and vote to affect the priority of the items