Hey @luggie, what are you after? The list of rgb, rgba or hex string for the corresponding colorscale?
If this was the case, you could make use of the swatches()
function:
import plotly.express as px
fig = px.colors.sequential.swatches().to_dict()
d = dict()
for trace in fig['data']:
colors = trace.get('marker').get('color')
name = trace.get('y')[0]
d[name]=colors