The colossus' attack used to be a sweeping beam which would destroy one unit, then sweep to another unit and destroy it, continually destroying weaker enemy units. However, the attack could only damage one unit at a time. The attack was later changed to a "spray" of beams capable of targeting five units. The attack has more recently changed to resemble the original sweeping animation, but continuing to inflict splash damage.
By June 2008, the attack animation was changed to be a sweeping beam, with the animation taking about a second to complete. Despite the new appearance, all targets continued to take damage simultaneously. The attack always strikes a linear area perpendicular to the direction the colossus is facing. This allows for a fine degree of control.
The attack was weak against buildings at BlizzCon 2008 but the damage figures were more recently altered.
The colossus' cooldown was lengthened between BlizzCon 2008 and January 2009, but its damage was also increased.
The beams could not be stopped by a mothership's Time Bomb ability.
↑The artists are still working with what would look best on the Colossus. In the latest build, many have seen that there is a beam sweeping from one side to another as the current visual.
Please also note that this is temporary art still, and even though that beam does seem to sweep randomly, it is actually doing instant damage to the whole line rather than what the visual implies, which is doing damage from one side to the other. Karune. 2008-09-09. Is the Colossus's dual-beam back?Battle.net StarCraft II General Discussion Forum. Accessed 2008-09-09.
↑The Colossus always attacks in a linear area horizontal to where the Colossus is facing. This does take a little more coordination than a Hellion or Lurker, but will no doubt still be possible at a high skill level of play. Karune. 2009-04-28. Has the Colossus changed in recent builds? (post 7)Battle.net StarCraft II General Discussion Forum. Accessed 2009-04-28.
↑Even though the beam is currently shown visually in various ways, the damage is done to all units in that straight line at the same time instantly. That line will always be based on the position you are attacking from, so in that way there is a lot of control as how to use the Colossus. Karune. 2008-10-20. Karune: Colossus. Battle.net StarCraft II General Discussion Forum. Accessed 2008-10-20.
↑Colossus is Tier 3. He has a very powerful attack that strikes in a line relative to his position. He is a vital weapon against Terran infantry and Hydralisks which have become more of a threat when being protected by Roaches. Against Terrans you can go High Templar to deal with infantry, but Ghosts can really ruin that. Colossus is a safer choice.
The original attack is not coming back. The old beam was just "more damage." Simple, but not fun. The current Colossus weapon encourages micro since it really matters who you shoot and the angle you shoot them from. Fortunately since the Colossus can step up and down cliffs and over friendly units he can move to the optimal position if you are fast enough. The biggest problem he has right now is with Neural Parasite on the Infestor. It's really giving the Colossus a hard time. We are working on that today. Cavez. 2009-05-15. Regarding the most honourable Colossus. Battle.net StarCraft II General Discussion Forum. Accessed 2009-05-16.
↑ 11.011.1The Colossus in the latest round of balance has had it's damage increased, with its attack speed decreased a bit, giving it some more burst. With a couple of these on the field, it is quite effective at decimating armies of light armor units. Karune. 2009-01-28. colossus attack. Battle.net StarCraft II General Discussion Forum. Accessed 2009-01-28.