People who make data visualizations should try to learn the "rules of thumb" to not confuse or exclude readers:

1) Avoid contrasting red/green and blue/yellow, as these are common colorblind pairs.

2) Pick shades that still look different when shown in grayscale.

3) All bar charts should have 0 at one end.

4) Please no 3-D pie charts.

To find good color palettes, check out https://colorbrewer2.org