Color Image Operation improvements

[jnation3406]

This issue will keep track of Color Image Operation UI Improvements:

• Allow changing selected color within scaling view (last view) in the Operation Wizard for Color Image Operation
• Allow selecting composite algorithm within the scaling view, which effects how the composite image will be rendered
• Allow selecting scale algorithm on the scaling view, which effects how both that individual image and how the composite images are rendered.

Both changing the scale algorithm and changing the composite algorithm involves implementing those algorithm options into the web workers in the UI code.