Improve colour coding

[TomNaessens]

Colour coding can be made more clear. Todo:

• Limit the color code to the column it's relevant for (e.g. mark "Brought back" column green or red instead of the whole row), this will allow us to add more colours on other columns (e.g. mark the column "Picked up" red when there's too much items picked up)
• mark the column "Picked up" red when there's too much items picked up
• mark the column "Brought back" yellow or orange when there's too much brought back than picked up originally
• look to other places where it's useful