I\'d like design a chart and set the colors from a single exemplar. Same way as in Excel\'s:

Roderick , the @mghie links are great to start, additionally try out the Colorlib Delphi Library , wich lets you convert between color models as well as HTML color conversion utilities. is very complete, full source code included and freeware ;).
check the demo application , in this image you can see a blue pallete generated using this library.