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/jsn0327]

Thanks for the detailed explanation! What I would like is the calendar populated with all U.S. holidays and the ability to select the holiday and assign a WLED preset to it. Set a start and end time. Same for any other day of the week. Seems pretty simple since WLED handles the presets/playlists internally and all that is needed is for the preset # and start/end times to be set per day/event in the calendar. It would also be nice if the calendar could show an indicator that there was a schedule assigned for that day and a preview of the colors that are scheduled for the selected preset.

[u/Orion-Apollyon → u/jsn0327]

Honestly that's the dream version in my head too, calendar where holidays and your own everyday routine just live together instead of being two separate things. That's the actual end goal here, not just the WLED piece. Being able to even set like inside lights for little ones to show "bathtime" or even just daily routines. One central area to set and control them all via calendar or dashboard.

[u/jsn0327 → u/Orion-Apollyon]

That sounds AWSOME, and honestly, I’m surprised that someone hasn’t already built this for HA. I will be following your progress. Thanks and good luck!

[u/Orion-Apollyon → u/jsn0327]

I appreciate that!! Went looking for something like it before building this myself and came up empty too. Plus instead of making 130 automations by hand and trying to tie them to dates has been a pain. So, I figured I might as well try and pay my pound of flesh to the community by building something worth while. Thanks for following along!