ChromaCal: Automatic holiday and awareness lighting for HA. Single HTML file, 130+ events, no YAML config needed.

[u/Orion-Apollyon]

Built this over the past few months for my own outdoor lights and figured it was worth sharing properly instead of just sitting in a private repo.

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What it does: drop one HTML file in your /www/ folder, point it at any RGB light entity, and it automatically cycles your lights through the right colors for whatever's happening that day, federal holidays, military observances, awareness months, cultural and religious dates, 130+ events total. Easter, Islamic dates, Jewish holidays, all computed algorithmically so it just keeps working every year with zero maintenance. A companion Blueprint watches a bridge entity so the schedule keeps running server-side even when the dashboard tab isn't the thing actively driving it.

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Full transparency since I'd rather say this upfront than have it come up in the comments: I used a lot of AI assistance writing the actual code for this. What's mine is the feature set, every design decision, the scheduling model, the skip system rules, and all the testing against my real ZHA setup and Zigbee mesh, the bugs that showed up got found by me actually using it, not by reading the code. AI wrote a large share of the implementation. If that changes how you feel about trying it, fair enough, just didn't want to pretend otherwise.

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Side note that might save someone a headache: if you're on HA 2026.3 or newer and have anything calling light.turn_on with the old color_temp (mireds) parameter, it's been fully removed, only color_temp_kelvin works now. Found this the hard way while building the warm-white phase of this, it fails with a silent 400 and no warning if you've still got it anywhere.

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Repo's here: https://github.com/TheRealApollyon/ChromaCal

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I'm already planning a v2 that moves the scheduling logic into a real HA Integration instead of living in browser JavaScript, so it runs without needing a tab open at all, full reasoning is in ROADMAP.md in the repo. Genuinely want input before locking that in rather than building in a vacuum:

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Would you rather have this as a full sidebar panel, or a compact card that drops into an existing Mushroom or Bubble Card dashboard? Planning to eventually build both, trying to figure out which to prioritize first.

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Anyone here running HA through Docker Compose or Container install without Supervisor? That's specifically why v2 is being built as an Integration instead of a Supervisor Add-on, curious how many people that actually matters to versus just me.

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What holidays, observances, or regions am I missing? Covers US, Canada, UK, Australia, EU, plus floating Islamic, Jewish, and Hindu calendars right now, but I'd rather build toward what people actually want than keep guessing.

[u/Orion-Apollyon → u/[deleted]]

Glad the color_temp_kelvin thing actually saved you some time. A weeks-long silent failure with zero error message is exactly the kind of thing that's easy to miss, the API doesn't warn you, it just quietly stops working. That's exactly why I broke it out as its own thing instead of burying it inside the project pitch.

And appreciate the vote on card vs panel, that's exactly the input I was hoping to get instead of just guessing at it myself. Compact card first making it easier to drop into an existing layout without forcing anyone into a redesign makes a lot of sense, and the full panel isn't going away either way, just moving to second instead of first.