This capability may not initially be obvious, but there is a way that the color of CText fields can be adjusted using script code.  In the case of adjusting text color for CText fields, it can be done at the level of the Component object.

The text color property is not adjustable on each individual CText field object, but it is adjustable across all CText fields within a form from the Component object.  In fact, there are actually two different colors that can be configured for CText fields from the Component object:

Me._component.HighConfidenceCTextFieldColor

Me._component.LowConfidenceCTextFieldColor

The HighConfidenceCTextFieldColor property determines what color to display the text in after character recognition has been completed with “high confidence” of the recognition level.  The LowConfidenceCTextFieldColor property determines the color that text is displayed in after recognition with a lower confidence level.

The default settings for these properties are Blue and Red colors. However, they can be adjusted by setting the properties to a Color object:

Me._component.HighConfidenceCTextFieldColor = System.Drawing.Color.Green

This is a change that can be made from within script at any point in the form.  The change will take effect immediately and will apply to characters already displayed in CText fields and to new characters that are added.  Just remember that it will apply to all CText fields contained within the form where you are adjusting the properties.