Creates a YIQ colour object from fractional values 0 .. 1.
Color::YIQ.new(0.3, 0.2, 0.1)
8 9 10
# File 'lib/color/yiq.rb', line 8 def self.from_fraction(y = 0, i = 0, q = 0, &block) new(y, i, q, 1.0, &block) end