ws2812b on pcb not white

it's a setinterval..... it loop
I'm working with espruino mini unpinned.

I think i have alway the same prob with the way to powering circuit (leds + espruino)if i need more than 400mA and using usb for programming at the same time... i need lot of power for the leds...
I'm confuse because usb power the board!
how to connect heavy power during developping time with usb plugged? and have same power without usb connected...
On my previous work i do not need power and using for powering oled screen... we've (you in fact) find the solution.
I'm confuse... always and always... sorry... when i've read your tech doc about powering, i'm confuse... for a non english reader, i find your explanation to ambigious (i'm sorry to have to say that...), the way you build your sentence is not univoc (one way) for my understanding level.
so i'm confuse and i don't know if i had to do that way or this way... do i have to bridge some thing on the back of the board????
I've roasted, one board... i was desesperate to do that and i want to avoid to do that again, just because i'm enable to understand how to wiring power on the espruino...

Can i power the espruino's board and my leds by the same way
Vin -> 5V and vBat -> Leds?

I think it's a power prob.... and perhaps a logic level prob... but...

regards

é.