Colour is represented as 4 components, each of which is a floating-point value from 0.0 to 1.0.
The 3 'normal' colour components are red, green and blue, a higher number indicating greater amounts of that component in the colour. The forth component is the 'alpha' value, which represents transparency. In this case, 0.0 is completely transparent and 1.0 is fully opaque.
hahaha... i dont know how i could have missed that ... i still am confused on why they want to use a 0-1 range for colors, when most artist standard programs use 0-255. I will have to figure a way to adjust for when artist want to use their standards to ogre's code.
0-255 is generally better for exact precision with 32-bit colour.
Whilst floating point values ranging from 0.0f to 1.0f provide enough precision, you'd need to convert from the 0-255 value to be exact.
Primarily though, 0.0f to 1.0f is better for math operations (adding colours, multiplying colours, etc).
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