The Package originator can control the colour of the Ink signatures added to a document during a signing.
When creating and customizing a Package, click on the Advanced tab in the Package Options.
Under Advanced, there is a drop-down to select the signature ink colour used while signing a document. By default, Blue is selected.
Other available options are Black, Red and Green.
You can set the option you want for all your future Packages by updating the
Signing Defaults values: Set Your Signing Defaults
During a signing, clicking on a text field that is added to a document displays some options at the top. When clicked, the paintbrush icon allows you to change the colour of the text.
There are 4 colours to choose from. By default, the text colour is black.
Colour can be changed for existing text and also for the text fields added on the fly during a signing.