Daily Updated Model with last two days data - maintain latest day colour and same for latest -1

 I have a report which looks at a dataset column that has 3 values. 0 for all values except the latest day which is set to today's date and the day before it which is set to today's date - 1. I have the visual filtered to only show values in the column greater than 0 which leaves me the two rows I want. I am then showing these 2 rows by a data column. I make my area chart and then customise the series to show each in a different colour. My problem is that each day the colours I have set change when I want them to stay constant (i.e. latest day is always green and the latest -1 day is always blue). I believe this is because I am using the date column as the series and the dates change. How can I make sure the visualisation keeps the colour based on the latest date rather than the actual date in the column. 

A worked example:

Today is the 7th August. My two values are 7th August (Green) and 6th August (Blue). Tomorrow I want to show 8th August (Green) and 7th August (Blue) but currently the model will show 8th August (Random) and 7th August (Green).