Here is a list of occurrances of "all" / "every" (Greek πᾶς, Strong's 3956) wherein the NWT (not the revised one) has "other" inserted with it:
Mt 6:33; 26:35; Mk 4:13, 32; Lk 11:41, 42; 13:2, 4; 21:29; Jn 2:10; 10:29; Rom 8:32; 1Co 6:18; 12:26; Php 2:9; Col 1:16, 17, 20
If you have access to the WTLibrary, just copy the line and paste it into the search box of the WTLibrary and it will create a listing of those verses. In many cases English idiom allows for it. Lexicons also define πᾶς (pas) as "each, every, any" "all," "any and every," "whole," "every kind of, all sorts of." (All these definitions were given in Bauer's 3rd edition Lexicon - BDAG, pp. 782-84)
Note that in some cases the NWT has brackets "[ ]" around "other," and in some cases it doesn't. The more recent versions of the NWT (2006 and later) have the brackets removed entirely.
I think the arguments for and against "other" in Colossians would have to be classified as theological arguments. The language itself, both Greek and English, allow for it as one possible way of translating it.
Bobcat