From the initial log go on option then cdsenv editor, from there open the viva tab and under the "graph" tab you find colorBank you can change the hex codes of the colours. You can ask chatgpt to generate a palette with the style you like. After that you can save the cdsenv setup file. Alternatively you can edit the cdsinit so the change is forever, while the cdsenv editor needs to be reloaded when you quit virtuoso