You guys are totoo fast for me ;)
My solution which is similar to's @cormullionto @cormullion's:
hexToRGB[hex_String] :=Module[{RGB},
RGB = StringCases[hex,
RegularExpression["^#(\\w{2})(\\w{2})(\\w{2})"] -> {"$1", "$2",
"$3"}] // Flatten;
RGBColor[FromDigits[#, 16]/100 - 1 & /@ RGB]
]
Graphics[{hexToRGB["#A4A4A4"], Disk[]}]
P.S.: Things are not always just #000000#000000
and #FFFFFF#FFFFFF
. It's mostly a varying of shades of #A4A4A4 #A4A4A4
:)
EDIT
PieChart of the sector angles proportional to {R, G, B}
hexToPiechart =PieChart3D @@ {ToExpression@#/255. & /@ (StringCases[#,
RegularExpression["^#(\\w{2})(\\w{2})(\\w{2})"] -> {"16^^$1",
"16^^$2", "16^^$3"}])} &;
hexToPiechart["#A4A4A4"]