Is it possible for an LED to change it's tint depending on the driver?

I got a SR3 off the marketplace and wasn't thrilled with the tint or the level of throw from the light. I had a Quark Neutral head laying around so I took the LED pill and unsoldered it. I removed the LED from the SR3 and soldered in the Q3 5A from the Quark.

I think it is a great light now, much floodier with a really bright beam; however, the LED is not as warm as it was in the Quark head. I had two of these heads and when shown at a wall side-by-side they were nearly identical. No when I shine the modded SR3 alongside the Quark 123 Neutral head there is a big differen - the SR3 is much cooler.

So my - question: Is it possible that a warm LED will be appear cooler or warmer depending on the driver pushing it?

Chromaticity (tint) definitely can vary with drive current level. There is also a separate issue of white point stability vs LED junction temperature (running the LED hot can produce long term tint shifts).

I assume you are using dealing with a Cree XR-E LED? Last I saw, Cree spec'ed their XR-Es with CCT <5000K at a max of 700mA drive current. If your SR3 has a drive current of say 1000mA vs some lower level for the Quark, that can easily explain the shift from warm to cool white.

The main issue with warm white LEDs is stability of the phosphor when driving the LED hard. The red components of the warm white phosphor can degrade, resulting in a tint shift towards cooler color temps, and the LED can quickly change from warm white to cool white.

Interesting - thanks for that information. And yes an IMR16340 was delivering jsut over 1.1A at the tailcap into the circuit at the high setting. So I guess it is possible although the heat sinking is really solid and the body never got more than just a little warm.

At the low #1 setting of the SR3 it is pushing about 0.015Amps at the tailcap on a RCR123 cell. At high it si pushing ~1.1A from RCR123 and over 1.2A from a CR123 primary. I didn't do any measurements at the LED itself.

Can anyone recommend a nice high CRI neutral or warm (around 4000 would be great) that would give me 1-2 lum at that low current and handle the ~1+ driving Amps of the circuit on high? Also where would I buy just one or two?