[Explore] Linear color scheme options do not work

[geido]

While scrolling the Linear color scheme options, suddenly all the options become the same.

How to reproduce the bug

1. Go to the "Vaccine Candidates per Country & Stage" sample Chart
2. Click on "Linear color scheme" under "Heatmap options"
3. Scroll the options to the bottom and up a few times
4. Suddenly all the options become the same

Expected results

While scrolling the color scheme options should not become the same

Actual results

All color scheme options suddenly become the same while scrolling

Screenshots

DEV.Vaccine.Ca.mp4

Environment

(please complete the following information):

• browser type and version: Chrome 95.0.4638.54
• superset version: master

Checklist

Make sure to follow these steps before submitting your issue - thank you!

• I have checked the superset logs for python stacktraces and included it here as text if there are any.
• I have reproduced the issue with at least the latest released version of superset.
• I have checked the issue tracker for the same issue and I haven't found one similar.

[geido]

@junlincc @jinghua-qa FYI

[geido]

The same thing happens with the country color scheme. This is possibly affecting all the places where the linear color scheme is used