# Changing Light RGB Color using a variable

**URL:** <https://discourse.nodered.org/t/changing-light-rgb-color-using-a-variable/52522>\
**Category:** General\
**Created:** [21 October 2021 17:17 UTC](https://discourse.nodered.org/t/changing-light-rgb-color-using-a-variable/52522 "2021-10-21T17:17:37Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![PapaZ](https://avatars.discourse-cdn.com/v4/letter/p/a88e57/32.png) [@PapaZ](https://discourse.nodered.org/u/PapaZ)\
**Post date:** [21 October 2021 17:17 UTC](https://discourse.nodered.org/t/changing-light-rgb-color-using-a-variable/52522/1 "2021-10-21T17:17:37Z")

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Hello everyone, I'm new to Node-RED but I've played around with programming for a while. What I'm looking to do seems easy but I can't figure out how to make it work. I query a Weather site to get Weather information. I've created a Flow variable that contains the value for a tempature. I want to change a light color to reflect that variable, something like rbg\_color: [0,0,variable]. I've tried different syntax combinations and just can't get it to work. I'm using a Call Service node to send this information to Home Assistant. I've spent many hours on Google without finding anything that helps. I hope this forum can shed some light or a direction to help me resolve this.

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**Author:** ![E1cid](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/e1cid/32/77971_2.png) [@E1cid](https://discourse.nodered.org/u/E1cid)\
**Post date:** [21 October 2021 17:44 UTC](https://discourse.nodered.org/t/changing-light-rgb-color-using-a-variable/52522/2 "2021-10-21T17:44:44Z")

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This could be done many ways but here is 1 example using a range node and a change node.

```auto
[{"id":"86bc09d2.197af8","type":"inject","z":"b779de97.b1b46","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"10","payloadType":"num","x":150,"y":4680,"wires":[["eed63582.5c5e98"]]},{"id":"eed63582.5c5e98","type":"range","z":"b779de97.b1b46","minin":"-20","maxin":"40","minout":"0","maxout":"255","action":"scale","round":false,"property":"payload","name":"","x":330,"y":4700,"wires":[["a39fc78d.8e1838"]]},{"id":"1da1b728.0edc39","type":"inject","z":"b779de97.b1b46","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"20","payloadType":"num","x":180,"y":4720,"wires":[["eed63582.5c5e98"]]},{"id":"a39fc78d.8e1838","type":"change","z":"b779de97.b1b46","name":"","rules":[{"t":"set","p":"rbg_color","pt":"msg","to":"[0,0,$round($$.payload)]","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":530,"y":4700,"wires":[["148aa5f6.67a06a"]]},{"id":"148aa5f6.67a06a","type":"debug","z":"b779de97.b1b46","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"rbg_color","targetType":"msg","statusVal":"","statusType":"auto","x":610,"y":4760,"wires":[]}]

```

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<div class="post-metadata">

**Author:** ![PapaZ](https://avatars.discourse-cdn.com/v4/letter/p/a88e57/32.png) [@PapaZ](https://discourse.nodered.org/u/PapaZ)\
**Post date:** [21 October 2021 19:28 UTC](https://discourse.nodered.org/t/changing-light-rgb-color-using-a-variable/52522/3 "2021-10-21T19:28:36Z")

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Appreciate the quick response but how do I input this into node-RED?

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<div class="post-metadata">

**Author:** ![PapaZ](https://avatars.discourse-cdn.com/v4/letter/p/a88e57/32.png) [@PapaZ](https://discourse.nodered.org/u/PapaZ)\
**Post date:** [21 October 2021 19:35 UTC](https://discourse.nodered.org/t/changing-light-rgb-color-using-a-variable/52522/4 "2021-10-21T19:35:36Z")

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Ignore last post, figured that part out. Thanks again

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<div class="post-metadata">

**Author:** ![PapaZ](https://avatars.discourse-cdn.com/v4/letter/p/a88e57/32.png) [@PapaZ](https://discourse.nodered.org/u/PapaZ)\
**Post date:** [21 October 2021 20:03 UTC](https://discourse.nodered.org/t/changing-light-rgb-color-using-a-variable/52522/5 "2021-10-21T20:03:58Z")

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E1cid...hate to be a pain but I still can't figure out how to input this into a 'Call Service' node. I hopefully attached the appropriate code for you to see what I'm doing.

[{"id":"8ad312da47accf81","type":"api-call-service","z":"e3336dd6041e40a8","name":"B1","server":"ea96c16f.d336c","version":3,"debugenabled":false,"service\_domain":"light","service":"turn\_on","entityId":"light.b1","data":"{"rgb\_color":[0,0,0]}","dataType":"jsonata","mergecontext":"","mustacheAltTags":false,"outputProperties":,"queue":"none","x":1060,"y":580,"wires":[]},{"id":"ea96c16f.d336c","type":"server","name":"Home Assistant","version":1,"legacy":false,"addon":true,"rejectUnauthorizedCerts":true,"ha\_boolean":"y|yes|true|on|home|open","connectionDelay":true,"cacheJson":true}]

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<div class="post-metadata">

**Author:** ![E1cid](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/e1cid/32/77971_2.png) [@E1cid](https://discourse.nodered.org/u/E1cid)\
**Post date:** [21 October 2021 20:15 UTC](https://discourse.nodered.org/t/changing-light-rgb-color-using-a-variable/52522/6 "2021-10-21T20:15:32Z")

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I do not us Home Assistant, but looking at your code posted it looks like it accepts jsonata in the api-call-service node. If so you can probably copy the expression from the change node and use it direct in the api node.

when posting code you need to use the \</\> button and paste between back ticks, otherwise the code is corrupted by the forum formatting.

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<div class="post-metadata">

**Author:** ![PapaZ](https://avatars.discourse-cdn.com/v4/letter/p/a88e57/32.png) [@PapaZ](https://discourse.nodered.org/u/PapaZ)\
**Post date:** [21 October 2021 20:44 UTC](https://discourse.nodered.org/t/changing-light-rgb-color-using-a-variable/52522/7 "2021-10-21T20:44:21Z")

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That worked.....you the man E1cid.....thanks again

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [20 December 2021 20:45 UTC](https://discourse.nodered.org/t/changing-light-rgb-color-using-a-variable/52522/8 "2021-12-20T20:45:18Z")

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