Hi Viktor,
The legacy themes were provided in order to facilitate the migration from the discontinued Telerik MVC Extensions to Kendo UI and make the process faster and less hassle-free. However, as Kendo UI evolves and new widgets and features are introduced, moving away from the legacy themes becomes a necessity. In case the web application you are working on has strict requirements on the color scheme you can either override some colors in an existing theme via additional CSS or use the ThemeBuilder which is able to tweak an existing theme via a WYSIWYG interface.
Regards,
Iliana Nikolova
Telerik
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