Constructors and set-function: 
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Default Constructor                         : (  0,   0,   0)
Constructor for arbitrary color (63,127,191): ( 63, 127, 191)
Constructor for gray value 31               : ( 31,  31,  31)
set color to (15, 31, 15)                   : ( 15,  31,  15)

Operators and named colors:
---------------------------
White - Blue                                : (255, 255,   0)
Cyan * 0.5                                  : (  0, 127, 127)
... + RGBColor(127, 0, 127)                 : (127, 127, 254)
RGBColor(127, 0, 127) * 2.0                 : (254,   0, 254)
!... - RGBColor(1, 0, 1) * 2.0              : (  0, 255,   0)
42 * RGBColor(1,2,3)                        : ( 42,  84, 126)
(to3 != Magenta)                            : true
(to4 == Green)                              : true

Performance test:
-----------------
Performance test (additions)                : OK (slowdown factor < 1.1)