HI @nikhil_cr - Thank you for your question. We've prioritized visuals that typically used series to have the additional color tray you are accustomed to seeing. I do see a recent Jira has been logged for this, so it is on the product team's radar.
Until then, you might be able to force the color series at a dashboard level if all the other insights on the page have insight-level color options. More details can be found here: https://community.incorta.com/t5/dashboards-analytics/changing-colors-in-your-dashboard/ta-p/1413