Matplotlib default colors used to be non colorblind friendly so we had to manually set colors on some examples, which makes them a bit ugly. The new defaults are now OK for colorblind people, so we can just rely on them.

Here are a few examples that are a bit ugly and that could probably rely on matplotlib defaults:

• https://scikit-learn.org/stable/auto_examples/cross_decomposition/plot_compare_cross_decomposition.html#sphx-glr-auto-examples-cross-decomposition-plot-compare-cross-decomposition-py
• https://scikit-learn.org/stable/auto_examples/classification/plot_lda_qda.html#sphx-glr-auto-examples-classification-plot-lda-qda-py
• https://scikit-learn.org/stable/auto_examples/linear_model/plot_logistic_multinomial.html#sphx-glr-auto-examples-linear-model-plot-logistic-multinomial-py

There are probably other plots that could be made prettier (all examples are here: https://scikit-learn.org/stable/auto_examples/index.html)

Please comment below to indicate below which file(s) you want to work on so that others don't pick the same files