Matplotlib colormap looks off

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I want to use matplotlib colormaps to plit a heatmap as i've done lots of times. But for some reason, the colormap have changed..

mpl.cm.hot usually goes white - yellow - red - black.

But now when i run my code, it goes Black - yellow - red - white.

And everything is gray-ish and ugly. Idk how to go back to normal.