Can I create a custom chart color palette?

I am making a large number of charts - for which I want roughly the same sequence of colors, but those are charts that include sequences that are much longer than the 6 colors in the "professionally designed" chart colors (sometimes as many as 15 or 20 different items). The automated sequence that results is the same set of colors, but fading in brightness and intensity. These charts end up virtually unreadable.

I have used the color wheel to select and create many colors that I want, they are saved as custom swatches. But every new chart I create has to have this sequence of colors applied.

I am looking for a way to create my own custom method to assign colors in a sequence, but aside from just adding colors to the palette, I would really like to find a way to save a sequence and then select and apply it to the chart.

Thanks in advance!