bsenthilbalu opened a new issue, #37991: URL: https://github.com/apache/superset/issues/37991
### Bug description **Summary** In Superset v6 (exact version/build below), the Calendar Heatmap chart shows no tooltip content in Light mode when hovering over cells. Switching to Dark mode reveals tooltip text, but it’s low-contrast/hard to read. This appears to be a theme/contrast regression or style override affecting ECharts tooltip rendering for this viz. **Screenshots / GIF** Light mode (empty tooltip): <img width="120" height="129" alt="Image" src="https://github.com/user-attachments/assets/3f3fa6c2-4d80-4beb-b413-6ce7929954ae"; /> Dark mode (barely legible): <img width="113" height="118" alt="Image" src="https://github.com/user-attachments/assets/317ca120-a5a3-4b98-81a5-f08acac0d20f"; /> **Environment** Superset version: v6.x **Steps to Reproduce** Create a Calendar Heatmap chart (ECharts-based) with: Time column (date or timestamp truncated to day) Metric aggregating to daily values (e.g., COUNT(*) or SUM(value)) Time grain: day Time range: e.g., Last 90 days Save and open the chart in a dashboard or Explore view. Ensure Light theme is active. Hover your mouse over any non-empty date cell. Observed: No tooltip content is shown (blank/empty tooltip). Expected: Tooltip should display date and value (e.g., Tue 20: 1). Switch to Dark theme. Hover again over a cell. Observed: Tooltip text appears but is low-contrast and hard to read (poor legibility). Expected: Tooltip should be clearly legible in Dark theme. Actual vs Expected Light mode Actual: Tooltip appears empty (content not visible). Expected: Tooltip shows date + metric with proper contrast (e.g., Tue 20: 1). Dark mode Actual: Tooltip shows content, but text has poor contrast (low legibility). Expected: Tooltip text meets contrast guidelines and is easy to read. ### Screenshots/recordings _No response_ ### Superset version master / latest-dev ### Python version 3.9 ### Node version 16 ### Browser Chrome ### Additional context _No response_ ### Checklist - [ ] I have searched Superset docs and Slack and didn't find a solution to my problem. - [ ] I have searched the GitHub issue tracker and didn't find a similar bug report. - [ ] I have checked Superset's logs for errors and if I found a relevant Python stacktrace, I included it here as text in the "additional context" section. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
