Hi Vallamkonda,
Did you check the Any Chart cheat sheet yet? You can find it here: https://docs.mendix.com/refguide/charts-any-cheat-sheet/
Also, for even more references, check the Plotly documentation here: https://plotly.com/javascript/reference/scatter/#scatter
It shows you how to modify the json, so that you can select the colors of your liking (and way more customization options).
Hope this helps.
If you have any further questions, please let me know!