As you have noticed, we have different colors associated with these buttons to quickly be able to tell the status of that particular sheet.

  Blue represents that no work has been done yet on the sheet.

  Orange represents that the sheet is complete, but has not been emailed or text to the customer yet.

  Yellow represents that the sheet has been emailed and/or text to the customer, but that they have not opened it for review yet.

  Green represents that the sheet has been reviewed by the customer, either via email or the link sent out by text.

The Same applies for your work order, or WO.