[Color] Add some clear template parameters for SFINAE

[Robin Dousse]

Is your feature request related to a problem? Please describe.
The Color class uses a lot the SFINAE principle in maybe too verbose way

Describe the solution you'd like
Make some type traits that are meaningful to the developer such as :

template<class DataType, class ODataType>
struct is_float_to_integer_cast
{
    static const bool value = (std::is_floating_point<DataType>::value && std::is_integral<ODataType>::value) &&
                              !std::is_same<DataType, ODataType>::value;
};