Corsair Link lights up our lives
RGB LED components are nothing without software to control them, and in the case of the ML120 Pro RGBs, that duty falls to Corsair's Link utility. On top of its system-monitoring capabilities, Link can be used to customize various settings of Corsair's wide range of compatible peripherals, including PSUs, heatsinks, entire fan-control hubs, and more. For the ML120 Pro RGBs, we get control over lighting color and eight prebaked animation effects.
To take control of the ML120 Pro RGBs, it's first necessary to tell the Lighting Node Pro that you want to control ML fans specifically on the channel they're connected to. Presumably, the Lighting Node Pro works best with only one type of fan connected to each hub. Selecting a different fan type from the menu of available options will set the entire channel to control that type of fan; there's no per-port customization from the RGB hub. Choose the wrong fan type and you probably won't break anything, but your connected peripherals may act weird or not work at all.
Link's eight prebaked lighting effects are reserved rather than rave-ready. Static displays a single solid color. Blink flips the fans' LEDs on and off at any of three speeds, and it can alternate between two selected colors or a random sequence. Color Pulse gently ramps the lights on and off, and it can alternate between two colors or a random sequence, as well. Color Shift smoothly runs the gamut back and forth between two colors, or it too can shift among random colors. Rainbow sets all four LEDs on each fan to the same color as they shift through the various colors of the visible spectrum. Rainbow Wave does the same thing, but each fan cycles through the spectrum using their individual RGB LEDs instead. Temperature lets you define three colors linked to temperature ranges from any one sensor Corsair Link can detect. Sequential lights up each LED on each fan in series, creating a kind of spiral or pinwheel effect. Most of these profiles allow for three animation speeds.
Overall, I'm pleased with the animation smoothness and color saturation that the ML120s produce. The fans don't have any trouble with tough "in-between" colors like oranges, and they can even produce a convincing white in a pinch.
One slightly clunky design choice in Link is that it's not possible to group illuminated devices in the interface and change them as a unit. Link does have a "Copy To" function that can apply a lighting effect configured for one device to a number of selected devices with a couple of clicks, and it does remember the devices you've copied lighting behaviors to in the past, so it almost works like a grouping feature. Still, it's not quite one-click convenience.
Corsair also seems to expect that users of its RGB LED products won't want to sync up their lighting with motherboards or other components in a system. The company hasn't developed a universal RGB LED sync standard of its own yet, nor has it opened up its own components to external RGB LED control sources (outside of one RGB LED RAM kit). That means the ML120 Pros will always require Link to be installed in order to modify lighting patterns or colors, and those patterns or colors won't (and can't) occur in sync with any lighting governed by a motherboard or other control source yet. This walled-garden approach may change eventually, but it's inconvenient now. It also doesn't help that Corsair RGB LED peripherals controlled by the company's Utility Engine, like the K70 RGB keyboard I have from some time back, can't sync up with Link-controlled peripherals or vice versa.
The RGB LED-obsessed may also be disappointed to find that Corsair doesn't offer any kind of custom animation programming for the Lighting Node Pro yet, as it does for its peripherals in its CUE software. To be fair, there's probably not a powerful ARM microcontroller inside the Lighting Node Pro as there is in the company's RGB LED keyboards, so custom programming opportunities may be limited. Still, folks with an extremely particular vision for how they'd like their RGB LEDs to look will need to content themselves with Corsair's eight included lighting patterns for now.