This spoiler-filled infographic by John LaRue tracks the colors worn by six of the main characters in Breaking Bad, and gives us a visual insight into how creator Vince Gilligan uses color to convey elements of the plot.
Edit: Commenter La Piquante notes that we can't ignore the work of costume designers Kathleen Detoro and Jennifer L. Bryan in developing these palettes.
Be sure to read LaRue's interpretation of the meanings behind these color choices. For example:
Skyler starts out blue, but turns dark once she starts to figure out Walt’s secret. Her timeline turns deep blue, almost purple, as her flirtation with Ted grows, and then it turns green once she discovers Walt’s stash of money. The more complicit she becomes in Walt’s criminal activity, the blacker her timeline gets to the point that it’s pitch black in season 4.