Power BI custom theme .json - multiple series customization - json

Question

I've been tinkering with .json file to create my own custom theme, however I am stuck on multiple choice setting. Example:
Area chart -> Format -> Data labels - > here I can customize the general setting for data labels, but what I would like to set up, is the "CUSTOMIZE SERIES" for each of the series. That is, I would like to have black text label color for the first serie, yellow for the second etc.
Below is the image from power bi for the category I am trying to customize:
Customize series in Power BI
Code for these labels:
"labels": [{
"show": true,
"color": {
"solid": {
"color": "#333333"
}
},
"labelPosition": "Under",
"fontSize": 14,
"fontFamily": "Arial",
"labelDensity": 30,
"showAll": true,
"enableBackground": true,
"backgroundTransparency": 70
What this .json code achieves, is that it sets up only the general settings for all the series. That is all series will have font size 14, font Arial, background transparency 70% etc. I would like to somehow index these series, so when this .json theme gets imported into power bi the first serie would have the customized settings that I've set up, second the same etc. E.g.:
"labelPosition": "Under",
"fontSize": 14,
"fontFamily": "Arial",
"labelDensity": 30,
"showAll": true,
"enableBackground": true,
Above are the general settings for all of the series, below would be the customized series
1. serie --->>>
"backgroundTransparency": 70
2. serie ---->>>
"backgroundTransparency": 60
3. series etc..