LOL. You can't.
Some color basics. There are solid colors, gradients, and patterns.
A solid is just that.... a solid color. One shade.
A gradient is one color shifting to another, and sometimes to another and another.
A pattern is a shape, or a group of shapes, made to repeat in a certain order. Usually a vector shape, that can have it's colors changed, but not always.
There are some exceptions to these three, but they're the basics. You can't take a jpeg and turn it into a solid, a gradient, or a pattern. Just how it goes.
Sorry to be a wet blanket. Just how our design life rolls...