Fixed Targeter-Box Coloring

[ghost]

Make the screenshot targeting box with dynamic coloring.

Make the screenshot targeting box able to change colors to the opposite color of its background as it moves, so it can always have high contrast with that background.

Allows users to always see what they're highlighting as the action, no matter what color background they're operating on. Otherwise, the user could end up with situations similar to those pictured below, where the box is very hard to see, decreasing usability.