Is the color of the population/housing bar on the Colony Summary screen an indicator for conditions that encourage population growth? Does a green population/housing bar indicate conditions that encourages growth, orange not?
As I understand it, keeping one or more open Hab units encourages population growth.
There is a large random element to population growth, but there are also modifiers. If I recall correctly from TB posts here, the probability of population growth is strong reduced after population reaches some multiplier of system quality--(the multiplier may have been 1.5?).
The TBs have also posted that having open housing units increases the chance of population growth.
Additional Hab Units can increase population growth rates. If the Colony has 20 Population, every additional Hab Unit above 20 will yield an adjusted percentage (assuming a single Colony empire) of approximately 4.45%
This is an unlimited scalar, but functions as a sub-ordinate to primary factors such as Quality-Population Max.