[evan_au]

It might be possible to disentangle them.

Astronomers have lots of experience estimating the type of star.
Knowing the distance (eg with Gaia data) removes one of the unknowns.

Knowing the spectrum of a star allows you to determine the chemical composition, which gives some hints about whether it is a nearby red dwarf (still young in a lifetime that could last > 10 billion years), or a distant red giant (exhausted the hydrogen or helium fuel in its core), and soon to expire dramatically
- The spectrum also allows you to determine the temperature more accurately than just the colour, as some spectral lines are more prominent in certain temperature ranges.
 
Looking at the brightness variation over time also shows that some stars are entering a period of oscillation, which tells something of the internal structure of the star.

For some stars, we see transiting planets, which can give an idea of the star's mass. In future, we may be able to do this for more stars, using a coronagraph to image planets that don't pass directly in front of the star.

[Janus]

It might be possible to disentangle them.

- The spectrum also allows you to determine the temperature more accurately than just the colour, as some spectral lines are more prominent in certain temperature ranges.
 

There is also spectral line spreading.  Since the atoms of the star's surface are moving in random directions, the light coming from them will show a small varation of Doppler shifts. The hotter the surface, the greater the range. This leads to a slight blurring of the spectral lines, with cooler stars blurred less, and hotter stars blurred more.

[Bored chemist]

It might be possible to disentangle them.

- The spectrum also allows you to determine the temperature more accurately than just the colour, as some spectral lines are more prominent in certain temperature ranges.
 

There is also spectral line spreading.  Since the atoms of the star's surface are moving in random directions, the light coming from them will show a small varation of Doppler shifts. The hotter the surface, the greater the range. This leads to a slight blurring of the spectral lines, with cooler stars blurred less, and hotter stars blurred more.

In some cases , we can do slightly better.
Superimposed on eth broadening, there's the fact that most stars spin (from our point of view). So one side is moving away from is and the other is moving towards us.
That doppler shifting can sometimes be seen too.

[Petrochemicals]

Some"stars" are actually galaxies. Points of light.

[evan_au]

one side is moving away from is and the other is moving towards us.

The NICER X-Ray telescope on the ISS studies the doppler shift of rotating neutron stars, in order to determine the mass vs diameter relationship, with the goal of better understanding the state diagram of neutronium.
https://en.wikipedia.org/wiki/Neutron_Star_Interior_Composition_Explorer

For some compact stars, a gravitational redshift has also been measured...
https://en.wikipedia.org/wiki/Gravitational_redshift#Astronomical_observations