The highlight is added to easily display that something other than specific numbers is going on within the file.
Green cells simply mean that the cell contains a sum formula, because the cell represents a subtotal, and the formula is used to create the XBRL mapping and calculation relationships when Platform is converting your files.
Orange cells mean that a rounding (usually + or - 1) has been added to the calculation to match your visual report. Note that such roundings can cause calculation inconsistencies - you can read more about these and how to avoid them HERE.