Hi,
it would be very helpful in Thunderbird if you could display various messages in colour, for example invoices to be paid in the inbox. To do this, add ‘Mark with Colour’ (or similar) to ‘Mark as Read’ and ‘Mark as Unread’ in the ‘Tools/Message Filters’ menu under ‘Filter Rules/Perform Actions’.
The entire message line/row is then displayed in the selected colour.
The same display in Thunderbird Android would of course be great.