Which of the following is not a recognized data type?

The correct choice is color because it is not a standard or recognized data type in most programming languages. In programming, data types are used to define the kind of data a variable can hold, such as integers, floating-point numbers, and boolean values.

Int, double, and bool are well-established data types. Int represents integer values, double is used for floating-point numbers (which can have decimals), and bool indicates a boolean value that can be either true or false. Each of these data types has a defined behavior and methods associated with it in programming languages.

On the other hand, while "color" can certainly be represented in programming (often as a custom class or a structure, or using color libraries), it is not a primitive or built-in data type like the others mentioned. This distinction makes it the answer to the question regarding which is not a recognized data type in the context of standard programming.