How to get a constant current from a DC power supply for high voltage/current
What you want is a constant current source.
The link goes to a selection of LED Drivers at Digikey that (approximately) meet your LED requirements.
You'll need to find one that fits your needs exactly.
Other suppliers carry LED drivers as well.  

You may well be better off looking in a building goods shop where they sell LED lights - they are probably cheaper than Digikey or other electronics suppliers.

Connecting the LEDs straight to a 36 Volt power supply is asking for dead LEDs.  You are not being overly cautious.  You MUST limit the current to the LEDs.

Any current limiting device will require at least a couple of Volts of headroom - the input voltage needs to be higher than the nominal voltage by at least a couple of volts.

You can build a current limiter from an LM317 or other voltage regulator.  You will have to watch out for the maximum voltage rating on the regulator, the maximum power rating of the regulator, and the voltage needed to drive the desired current through the LEDs.

Or, just buy a proper regulator (or 4, you need one for each LED) and be done with it.



Since your current power supply is from Delta, here's a selection of Delta LED drivers.



The LM317 datasheet has an example of a current limited regulator.  The current is set by one resistor (small value, relatively high power rating, couple of watts.)

But, it needs 3V above the nominal 36Volts for the LED to work with, so this circuit together with your 36Volt power supply won't work.

LM317 example: