Any advantage to powering WS2812 leds at lower than 5V?

[desertgreg]

Most projects I see power their WS2812 leds using a 5V power rail.  Internally there are 3 separate LEDs and the blue led only needs (I think) 3.5V.  My thought is, would there be an advantage if I tuned my buck converter powering the LEDs to output something closer to 3.5V instead of just using 5V?  It seems like this would allow the individual leds to do a smaller step-down to the LED voltage (though I don't know how ws2812's work internally).  Obviously if I get too close to the min voltage for the blue led, then it would stop working correcly.

TLDR: Would my device gain efficiency if it powers its ws2812 leds at 4V instead of 5V?

[mikeselectricstuff]

Yes it would be more efficient ( assuming your power supply is a switcher whose draw is proportional to output power, not output current. - reduce voltage until you see a drop in current draw, then increase a little. I've run short LED strips at 3.3v, though we didn't need blue in that job

Just make sure you allow for voltage  drop, especially when using LED tape

[Benta]

None at all.
Read and respect the datasheet. The 5 V is for the internal logic/drive and interface.

[mikeselectricstuff]

None at all.

Apart from saving up to 25% power, which may or may not matter

Read and respect the datasheet. The 5 V is for the internal logic/drive and interface.

The datasheet says 3.7-5.3v supply

[Benta]

The datasheet says 3.7-5.3v supply

Good.
Then continue your project with the OP on running them at 3.5 V.

[qtbits]

Rather late to the conversation... but heat would be another reason to test on lower voltages... I have a tight 10x10 grid of 2020s and at 5V and full brightness - it gets too hot to touch.

[baldurn]

The datasheet says 3.7-5.3v supply

That should probably be measured at the far end of the LED chain. There is going to be a voltage drop.