This inheritance list is sorted roughly, but not completely, alphabetically:

[detail level 123]

color	Structure for saving RGB colors
ColorGradient	Class for saving color gradients (palettes)
Plot	Base class for all plotting functionality
HeatMapPlot	Class for plotting a single TH2 (heatmap) and one corresponding legend
RatioPlot	Class for a rectangle plot displaying ratios
SingleRatioPlot	Class for a rectangle plot with the distributions in the upper pad and the ratios in the lower pad
SquarePlot	Class for a simple square-format plot
TLegend
Legend	Class for additional legend functionality, mainly additional constructors