Color tolerance is how great a color change is required before the tracer considers two areas to be a different color.

This setting is used for the final pass. It is similar to merging the edges of color transitions to simulate shading.

As a trace proceeds, the color tolerance is reduced from the initial value to the final value, so the initial value must be the larger.

For a trace using only a single pass only this value is used - Initial Color Tolerance is ignored.

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