This idiom isn’t terribly succinct, but it does suggest the sense of a frame — a boundary:

color inside the lines

To think or act in accordance with set rules. Likened to the way a child is encouraged to neatly color within the lines of a coloring book.

_{That poor girl is so rigid. I think she’s only capable of following rules and coloring inside the lines.}

_{Source: The Free Dictionary — color inside the lines}

Conversely, we have:

color outside the lines

To think or act in a way that does not conform to set rules. Likened to the way a child might color outside the lines of a coloring book.

_{My coworkers don’t always understand my ideas, especially since I like to color outside the lines.}

_{Source: The Free Dictionary — color outside the lines}

So: I’m not a color-inside-the-lines person. I like to color outside the lines.

This idiom isn’t terribly succinct, but it does suggest the sense of a frame — a boundary:

color inside the lines

To think or act in accordance with set rules. Likened to the way a child is encouraged to neatly color within the lines of a coloring book.

_{That poor girl is so rigid. I think she’s only capable of following rules and coloring inside the lines.}

_{Source: The Free Dictionary — color inside the lines}

Conversely, we have:

color outside the lines

To think or act in a way that does not conform to set rules. Likened to the way a child might color outside the lines of a coloring book.

_{My coworkers don’t always understand my ideas, especially since I like to color outside the lines.}

_{Source: The Free Dictionary — color outside the lines}

So:

I’m not a color-inside-the-lines person. I like to color outside the lines.