You may extract the exact colors that PieChart is using so you will not need to look for the specific color scheme it is using
Say you generate a Pie chart of 10 elements
g=PieChart[Range[10]]
The colors used by PieChart can be extracted (you need to drop the first two, so I use Drop...]
colors=Drop[Cases[g,_RGBColor,Infinity],2]
Now you can use the same colors as the PieChart inside Plot or any other graphics you would like
Plot[Evaluate[Table[n t, {n, 10}]], {t, 0, 1}, PlotStyle -> colors]
Although the above is a "quick" solution, it is also a "dirty" one, since it relies on the internals of PieChart. I would consider to use the same color scheme just by dictating both PieChart and Plot to use it (see the option for ColorFunction for both).
yehda
