@Wer90: I am with the Pro group here. After playing GalCiv2 extensively it always seemed to be a missing part that missed races were not even given a nod. The races are so very different at the beginning of the game with the racial bonuses, yet when they join your 'empire' they suddenly become 'your' race. I haven't modded GalCiv at all but from other games here is a whiteboard level concept of how it could be done and what might come from it:
A basic would be a simple bar on the planet screen fills with the banner color of the race based on percentage of planetary population. To get specifics, you could then have a tooltip show up when you hover over it that Shows the top 3-5 races by percentage with all the rest lumped into 'other'. So the tooltip might look something like:
Terren Alliance 54%
Dregin Race 21%
Altarian Resistance 4%
For the truly interested party, we can go further and via double click on the bar it could take you to the planetary details page (that I only looked at perhaps three times in GalCiv 2) where the demographics can really be laid out to include % for all races and the number of people/things that correlates with.
As for how the multiple population types would grow, well, that was already there in GalCiv2 in some form. There is most likely a population growth algorithm in the game that factors in planet type, racial bonuses, and technology/building/planet bonuses. I would suggest as a starting point to use the base growth rate of the species without any tech/building help and add a -25%ish base growth penalty to any race not of the players (because really, this is now a planet owner by [insert players race] and we get preference in breeding). Perhaps expand on this a bit to have a bigger/smaller negative based on the race relations (ie. arch enemy races would have a BIG problem with each other while two neutral races really don’t care)
Just having that, the information and basic population growth, would truly help my immersion to turn it less into a fun game to a immersive world.
Some additional features that I would have loved to have in GalCiv2:
Upon taking a planet have an option of how to 'deal with' the survivors that affects the players alignment and provides a bonus. In example:
"My lord, with the help of the dissidents from your propaganda efforts, we have taken the planet. What shall we do with the survivors?"
1) Reward them with full citizenship, we welcome those that support us (minor bonus based on race involved/number survivors; ie. iconion refuge population means planet gets a bonus to science)
2) Very good, however we cannot forget the crimes of the people. Place them under arrest and let them work to atone (production bonus, bigger negative hit on secondary race population growth.)
3) Excellent, however they are inferior and have the intelligence of farm animals. Luckily, they are delicious and the farms are empty. (all secondary races are removed, population growth bonus.)
Also, it would be nice if current events impacted planets. A complex system can be created with some simple rules. this could be made more complex just be adding more 'simple' rules to dictate how each individual race would handle the situation. IE the Dregin population doesn't care about being at war with other Dregin as much (or at all) when compared to say the Iconians who care very much about you killing other Iconians.
Change to how 'approval rating' of a planet is done
Proposed rule examples:
War discontent: Being at war with a faction will cause citizens that share a race with that factions primary to be disapproving
Alliance Approval: Opposite of above
War Crimes: Doing really mean things will cause a big spike of dissatisfaction among citizens of your empire that share a race.
Change to How Planetary Defense is calculated: Add the equation for 'soldier strength' of every race to every planet and have it be multiplied by the population % with result be the sum of the equation. I do not believe that is too far off from how it is currently calculated.
Immigration/Emigration. Influence attracts people from factions that have lower inflluence. Population growth bonus to secondary races on planets near borders becoming smaller the furthur in you go. Again, this would most likely be done via algoritm and build on everything else. If population actually means more then just tax farming and meat shields for a planet this would make influance an interesting sabotage mechanic.