Forerunner Monitors 343 Guilty Spark and 2401 Penitent Tangent.
About this creation
I built 343 Guilty Spark and 2401 Penitent Tangent rather quickly, as there isn't a whole lot to these monitors. I was only able to locate one white 'cap' piece for Guilty Spark, but the circular stud on the bottom works well enough. In the game, the sides of the monitors are indented and give off a weird glow, but I opted to simply put more translucent colored studs for the glow effect. I also Used tan for Penitent Tangent's body, as he is encountered in Halo 2 after being captured by the Gravemind. And those flood just love to cover everything they can in that puke-brown color.
A meeting of the minds... or machines.
"Greetings! I am 2401 Penitent Tangent. I am the Monitor of Installation 05."
"Oh dear. Containment protocols appear to have been violated."