Colonizing planets in foreign systems

A spaceport will allow you to trasnmit your supplys. It will tell you are transmitting supplies to your empire in the main screen on the top left.

Basically you need to build at least one space port in the forgin system to connect your new colony to the empire. There is a racial ability which allows you to do without the space port "hardy merchants I think" but if you don’t have it the space port is a must and preferably two in contested systems since losing your port colony or having it blockaded will then not prevent your system supplying the empire.

its a defalt tech in most games so I had to check its tL1 in industry

all you have to do is put it on the build Que as lack of a space port dosent stop suplys for building it seems just comunication back to the parent empire. Which is good as it would be a nasty catch 22 situation otherwise.

have you got any people on the colony as if the que says never thats the most common cause. Always load people onto coleny ships either automaticaly using the colony button or manualy using transfering them as cargo

It could also be that you are lacking the resources required to build it

There you go...Enjoy your new colony... Remember to defend it =)