The RK920 Rainbow keyboard uses single color leds (red, yellow, green, cian, blue, purple and pink) segmented into 7 zones to create a cool cascading rainbow effect. The numpad leds are all single color pink leds, while the navigation keys leds (End/PgUp/PgDn, etc) are all single color purple leds. The other single color leds are distributed evenly throughout. The single color led setup does limit the RGB potential of the RK920 mechanical keyboard, especially in custom mode as you cannot choose any color you want. That said, the overall color display and brightness is really nice. The rainbow led lighting comes through the key legends and top plate fluidly and vividly.


Aside from custom mode lighting, the RK920 Rainbow keyboard comes with 24 dynamic light effects and 6 game light modes, which light up specific keys on the keyboard. There is no solid (static) color options. In custom light mode, you can save up to 7 different color combinations and toggle between them right from the keyboard without any software. You can also adjust brightness (from 5 levels) and change speed of lighting effects.


Being a full size keyboard, the RK920 Rainbow mechanical keyboard is naturally larger than a tenkeyless keyboard. If desktop space is important or you have a small desk it's worth going for a smaller keyboard such as the RK Sink87G, which is an 80% mechanical keyboard with navigation keys. If you want something even smaller, check out the Redragon Anivia K614 60% keyboard.


The base of the RK920 Rainbow keyboard is naturally shaped at a 10 degree slope. The top row of keys measures 4cm high, while the bottom row of keys measures 3.5cm high. You can elevate the front a little bit higher (an extra 1cm) via the feet risers, which have thick silicone rubber that grips superbly on a smooth desktop, preventing the keyboard from sliding off while elevated. 


On the base of the RK920 Rainbow keyboard, there are also two small cutouts, which appear to be for a wrist pad, although there isn't one built-in like on the original RK920 keyboard. The RK920 Rainbow keyboard measures 44cm long and 13.5cm wide and weighs 860 grams. The non-detachable rubber power cable measures 1.6 meters long  and features a USB-A connector and ferrite bead inline the cable.


The stock keycaps on the RK920 Rainbow aren't PBT but they're almost as good, being double shot ABS so, the legend won't wear off. The RK920 Rainbow keyboard also has a standard bottom row so, it uses a 6.25U spacebar and 1.25U keycaps, which makes it easier when sourcing aftermarket keysets. 

Royal Kludge tends to use different brand switches for their keyboards, namely Cherry MX, LongHua, Outemu and Kailh, although they also use their own RK switches. LongHua switches are relatively unknown compared to Cherry, Outemu or Kailh, although LongHua switches have been around for a long time. In fact, the original RK920 keyboard (released 5 years ago) shipped with LongHua switches, which are actually made by Kailh. The RK920 Rainbow keyboard seems to ship with stock Cherry MX switches in some parts of the world (e.g. Australia), whereas in the UK, the RK920 Rainbow keyboard is only available in RK brown, RK blue and RK red switches (they have RK letters printed on them). 


If you prefer Outemu or Kailh switches, you will find these switches in the RK61 RGB keyboard (Kailh) and Redragon Deimos K599, which uses Outemu hot swap switches. Outemu switches are nice but, they can only be hot swapped with other Outemu switches. RK switches are universal but the switches on the RK920 mechanical keyboard are not hot swap-able, although it's worth knowing should you want to de-solder the switches. LongHua switches are universal too, so if you get a keyboard with with LongHua switches, you can interchange them with Cherry, Gateron, Kailh or any other switch brand.

The Royal Kludge RK920 Rainbow version comes with software support too, which is useful although limited. You get access to user profiles  as well as tweak the lighting and create macros (up to 3), which you can store on-board and play via the keyboard. The Royal Kludge software does not include button remapping; hence you cannot re-assign the keys on the keyboard. Accessories included are a velcro cable tie and keycap puller.


While most mechanical switches are clones of each other, performance does vary. For instance, RK red switches (50g) are heavier than Cherry Mx red (40g). In fact, the RK red, blue and brown switches that come with the RK920 keyboard have the same 2mm travel actuation and actuation force (50G) so, the only difference you get is the level of noise. Red switch is quieter, followed by brown and blue (loudest). You can buy the RK920 Rainbow 2021 version from amazon and Royal Kludge website. Check out the review of the Elf Pro K649 transparent keyboard, Garen K656 Pro. Royal Kludge RK89 and CASTOR K631 RGB