If you are going to alter your colours in your website systematically then as a first you need to use Themed Colours.
Xara provides the Palette from Image function to create five main Theme Colours with shade/tints that you can spin off from.
These are my default template Theme Colours:
Just by loading an image, I can change all these with one click.
When I have a client, I pick any photo they have or corporate colours and create a range of colour schemes.
With these I can run Accessibility checks and advise which are the best for the web.
My client colour schemes are using the image under the theme colour palette so very easy to talk over.
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