No. You are unable to make any changes to the five main workflow statuses in Karbon—Ready To Start, Planned, In Progress, Waiting, Complete.
However, under each of these main statuses, you have the option to create and set your own customized sub-statuses to suit your firm's needs. You can then use the main statuses as a workflow guideline.
To apply the sub-statuses to your work, from the main menu:
Click on Settings > Workflow
Click on Work Types
Click on the <Work Type Name> that you want to apply it to
Check the box beside each of the sub-statuses you want to appear