update plot aesthetics in example notebooks

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 91.12%. Comparing base (8db0f26) to head (e2cc332).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #170 +/- ## ======================================= Coverage 91.12% 91.12% ======================================= Files 95 95 Lines 5589 5589 ======================================= Hits 5093 5093 Misses 496 496 ```

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