How do i colour Sunburst rings in Plotly based on different conditions

Question

I am having trouble using plotly to colour certain data values in my sunburst visual. E.g. My data looks like the first code block below and i want my sunburst to colour the unknowns a certain colour e.g. black in my code. However, i can only pass through one argument using color=1. How can i pass in multiple values (so that i can color the unknowns in the different columns)?

6   5   4   3   2   1   weight
3   5   3   Unknown 10  11  1
3   5   3   Unknown 10  11  1
3   Unknown 3   Unknown 10  11  1
3   Unknown 3   Unknown 10  11  1
3   Unknown 3   Unknown 10  11  1
Unknown 5   3   Unknown 10  11  1
Unknown 5   3   Unknown 10  11  1
Unknown 5   3   Unknown 10  11  1
2   1   3   Unknown 10  11  1
2   1   3   Unknown 10  11  1
2   1   3   Unknown 10  11  1

My python code looks like the below.

import pandas as pd # import pandas
import plotly.express as px # import plotly package

df = pd.read_excel('data.xlsx',sheet_name="Sheet1")
fig = px.sunburst(df, width=500,height=500,path=[6,5,4,3,2,1], values='weight',color=1,color_discrete_map={'Unknown':'black'})
fig.show()