Negative voltage output Or Controling negative voltage I've got an RGB led strip I'm trying to control. It's a 12v, 4 pin strip. 
Pin layout seems rather odd to me as 1 pin takes 12v of power and 3 pins (that go to ground) control the colors. In other words, the LED colors are controlled by limiting outgoing voltage.




White- +12v
Green- Green in negative voltage
Red - Red in negative voltage
Blue - Blue in negative voltage


I've already made a similar setup that uses n-channel MOSFETS (or at least I think that's what they are) between the colored cables and the ground and Arduino power the MOSFET gates as necessary.

So my question is: is it possible to hook these LEDs up directly to arduino and control the negative voltage without aditional electronics?

As a slightly off topic question: Is there a specific name for elements that are controlled with negative voltages.



By the way, I'm using Arduino nano, although I don't think it is relevant at this point and I've got Mega and Uno aswell if needed.
No, it's not possible, since the voltages and currents involved (12V) are too high.  It will damage your board.

Your arrangement with N-channel MOSFETs is the correct arrangement.

By the way, you are not working with "negative" voltages at all - it's all positive - you just happen to be between the "load" and ground.

This is called a Low Side Switch since it is on the "low" (i.e., between the load and ground) side of the circuit.

The LEDs you have are in an arrangement called Common Anode in that the anodes (+ pins) of the LEDs are all tied together (common) and you control the cathode (- pins) of the LEDs.  It means you can use cheap N-channel MOSFETs that are (as you have seen) easy to control with a microcontroller.  The other arrangement, Common Cathode, where all the cathodes (- pins) are tied together and you switch the power to the anodes (+ pins) requires P-channel MOSFETs and N-channel MOSFETs to switch the P-channel MOSFETs, which increases costs.