px animations does not show correctly colors if all colors are not in the first frame

For example

import pandas as pd
import plotly.express as px
dataVals = {
    'Lat': [39.783730, 7, 39.783730, 39.783730, 20, -4.03, 39.783730, 36.82, 39.783730],
    'Lon': [-100.445882, 66, -100.445882, -100.445882, 70, 5.33, -100.445882, -1.29, -100.445882],
    'Value': [40, 12, 22, 3, 60, 23, 30, 100, 200],
    'Year': ['1985', '1990', '1990', '1990', '1990', '1990', '2000', '2000', '2000'],
    'Continent Color': ["a", "b", "a", "a", "b", "c", "b", "d", "a"]
    }
data = pd.DataFrame(dataVals)

fig = px.scatter_geo(data, lat="Lat", lon="Lon", size="Value", color="Continent Color",
                     animation_frame="Year", animation_group="Continent Color",
                     projection="natural earth", size_max=200)

fig.show()

(all points are displayed with the color of continent "a"). Reported by https://community.plot.ly/t/scatter-geo-only-shows-values-with-a-certain-color-if-i-have-multiple-years-as-the-same-year/35976. Other functions such as px.scatter have the same problem.

If all colors are used for the first frame, the problem disappears.

Start by running the provided pandas and Plotly Express example, then compare px.scatter_geo with px.scatter while tracing how animation frames and color values are assembled. Done means colors introduced after the first frame render with their own colors in animated charts, including the reported example.