Reddit reviews CablesOnline 4" USB 3.0 20-Pin Motherboard Header Female to USB 2.0 8-Pin Male Adapter (USB3-AD24)

Damn that's annoying.

Well if you've got spare USB 3.0 headers you can try getting one of these adapters to give yourself a USB 2.0 header:
https://www.amazon.com/CablesOnline-20-Pin-Motherboard-Adapter-USB3-AD24/dp/B00E42A4L0/ref=sr_1_1?s=electronics&ie=UTF8&qid=1526459010&sr=1-1&keywords=USB+3.0+20-Pin+Header+female+to+USB+2.0+female

That might do the trick. Think it's female to male ends you need. If not then plenty other option similar.

seems a bit over kill to me, but you got me started on the right path and i found this https://www.amazon.com/gp/product/B00E42A4L0/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

I'm unsure how well the Kraken X31 works without the USB connectivity (CLCs have worked for years without having it as an option). Allegedly it does work without it according to this post: http://www.overclock.net/t/1507682/kraken-x31-rattling-pump-noise#post_22811880 though YMMV.

The Internal USB2 cable & USB3 Header are definitely not physically compatible.

Three options:

1. Go without the USB connection, unsure if it will work, but should.
   
   
2. Rig something like this: http://www.frontx.com/cpx508.html to go from the back of your IO, back into your case, though I'm unsure if the X31 uses "all" of the USB2 header pins, or just the first row (it's infuriating how many manufacturers use the whole block for the equivalent of one USB connection).
   
   
3. 'give up' your USB3 headers, and use this: http://www.amazon.com/CablesOnline-20-Pin-Motherboard-Adapter-USB3-AD24/dp/B00E42A4L0 to convert the header to a USB 2 header.
   
   Option 3 is the most likely to work, Option 2 is the ghetto option, Option 1 would be giving up on some of the features you're paying for in your cooler.

theres usb 3.0 heads on the mobo right? can i jsut get a adapter?https://www.amazon.com/CablesOnline-20-Pin-Motherboard-Adapter-USB3-AD24/dp/B00E42A4L0
would this work?

Something like this might work

https://www.amazon.com/CablesOnline-20-Pin-Motherboard-Adapter-USB3-AD24/dp/B00E42A4L0