Colouring on Planner to differentiate between annual leave and other leave

Since Covid, we have been making an entry every day against employees to state whether they are in the office or working from home. This was helping us to monitor that if someone caught the virus, who else had been in the office on the same day so we could try to contain the spread.

Then, when we returned to the office properly, we introduced a hybrid working from home/office working policy and that requires colleagues to attend the office for a minimum of 3 days per week. This means that the whole planner is coloured pink to indicate that there is an entry. We are monitoring that everyone is adhering to the policy which is why their days in the office/home are being recorded.

My idea is that different types of leave are colour-coded so that when a manager looks at their team, they can see if they are on leave which they can't now as everyone has an entry on every day. If we had say, sickness indicated in blue, annual leave in green etc., the planner would become useful in the way that it once was.