Hello

I can move units to ship one at a time from colony.

Is it possible to select and move multiple units at once. If yes, then please help me I am unable to figure out how to achieve this.

Ctrl click the units or shift click the first and last unit of a block you wish to move and then move them to the ship.

shift click to select a group or block of units, while ctrl click to select multiple of single units.

and you can also do a combination of both methods as well to select the units you want

I wish I would have ask this in the forum when I was a newby, It took me 2 eras to figure this out...