A quick guide to fixing dim blue on addressable strips

I ran into this exact thing on my kitchen cove lighting last winter. The far end of my 5 meter run of WS2812B looked like a completely different color than the start when I set a pale blue, like a washed out grayish teal instead of that icy blue I wanted. Turned out it was mostly voltage sag. I fed power at one end only, and once I soldered a second feed wire to the middle of the run the blue came back to life at the tail.

The other thing that helped me was bumping the blue channel up in the WLED color balance settings. I left red and green alone and just pushed blue higher until all three looked even to my eye in a dark room. Cameras lie about this stuff badly. My phone made the blue look almost black when in person it was perfectly visible.

One thing I noticed on a cheaper strip I bought for the shed is that the blue LEDs themselves just seem weaker out of the box. Same power, same data, same settings, and blue is the runt of the litter. I stopped chasing it and just accepted that blue gets a boost in software. If your strip is new and blue is still terrible with good power, I would swap in a known good first pixel before assuming the whole batch is bad.

The camera point is huge, and it gets worse if your strip is behind any kind of clear cover. I do stage lighting installs, and I put a WS2811 setup behind polycarbonate on a bar sign about two years back. Blue has faded way faster than red or green since, because the plastic yellows a little and yellowing eats blue light first. So if yours sits behind acrylic or epoxy or even glass with a film on it, age shifts the balance too. I just nudge blue up every few months in the color balance and it looks fine again.

This explains a lot about my under cabinet lights. When I pick white they always look a bit yellowish to me and I could never figure out why, I guess the blue part is just too weak to balance it out. I tried turning the whole thing brighter but that just made the yellow worse. If I bump blue up like the second poster said, will that mess with how the other colors look, like will red start looking purple-ish or pink?

I chased this on a bookshelf backlight project and the culprit ended up being my feed wire, of all things. I'd soldered an injection point using some skinny leftover wire from a junk drawer and even a short run of that was choking the current before it ever hit the strip. Swapped in proper 18 gauge and the blue at the far end perked up right away. So if you're injecting power, check the gauge of the wire itself, thin stuff adds its own drop on top of whatever the strip is doing. To the under cabinet poster, bumping blue up shoud be fine, your whites will just shift a touch cooler which is usually what people actually want in a kitchen anyway.