2026.3.0: Convert Mireds to Kelvin

Configuration
1

Hello all,

In 2026.3.0, the color_temp is deprecated and must be replaced by color_temp_kelvin.

The fomula is

T(Kelvin) = 1,000,000 / Mireds

Hope that helps

4 Likes
2

This change was several years ago…
The errors that were happening in your system all this time just showed up now.
Also thin might help you…

3

Thanks for the context! Even if the change started a while ago, version 2026.3.0 seems to be where it’s finally failing for many of us.

Just wanted to share the formula in case anyone else hit the same wall today.

Cheers!

4 Likes
4

The implication for me is to scenes. I have hundreds of scenes involving WiZ bulbs that now fail silently. I’ve been blissfully ignorant of the whole kelvin/mireds thing until this morning, until my wife informed me that the lights in her office won’t turn on. Why? Apparently because HA stored that scene with a mireds reference when it was created, years ago, and I updated HA yesterday.

5

Because my scenes.yaml file is almost a megabyte, I made a backup copy then ran the following python script in my config directory. After reloading scenes.yaml, my household lights work again.

import re

with open('scenes.yaml', 'r') as f:
    content = f.read()

def mireds_to_kelvin(match):
    mireds = int(match.group(1))
    kelvin = round(1000000 / mireds)
    return f'color_temp_kelvin: {kelvin}'

# Convert color_temp values
content = re.sub(r'color_temp:\s*(\d+)', mireds_to_kelvin, content)

# Remove the now-invalid mired range attributes
content = re.sub(r'\s+min_mireds:.*\n', '\n', content)
content = re.sub(r'\s+max_mireds:.*\n', '\n', content)

with open('scenes.yaml', 'w') as f:
    f.write(content)
1 Like