Mathematica has many preset schemes, for example "DarkRainbow" and "FadingRectangle":
Histogram[RandomVariate[NormalDistribution[1, 0.2], 100],
ChartStyle -> "DarkRainbow",
ChartElementFunction -> "FadingRectangle"]

How can I get Mathematica to tell me the source code for these schemes? I want to reproduce "FadingRectangle", with some modifications of my own.
?System`BarFunctionDump`*. – J. M.♦ Oct 12 '12 at 8:31