Color picker doesn't reflect changes by color curve tool

[mmhmjanssen]

Using the pencil tool I created 10 big dots with the same Green en Blue value but with the Red value ranging from 10, 20, 30 etc to 100%, I used the Color Curve tool to modify the Red component only. While the colors on the screen truly reflect the changes, the Color Picker tool still shows exactly the same color as before applying the Curve Tool. I have to export the image and reload it into GIMP before I get the actual colors in the Color Picker tool. Am I missing something, or is this a bug?

[rich2005]

Not a bug as such but can be an annoyance.

Gimp 3 has layer effects - that fx you see in the layers dock.  That is a sort of invisible layer which lets you see what effect the tool will make without affecting the layer itself. It also allows going back and make corrections if the user does not like the effect.

see: https://docs.gimp.org/3.0/en/gimp-using-...fects.html

Two ways to get what you want
(1) Enable Merge filter in the tool dialogue.
or
(2) Click on the fx in the layer and there are options to apply - delete - hide.....

   

[mmhmjanssen]

(02-18-2026, 11:10 AM)mmhmjanssen Wrote: Using the pencil tool I created 10 big dots with the same Green en Blue value but with the Red value ranging from 10, 20, 30 etc to 100%, I used the Color Curve tool to modify the Red component only. While the colors on the screen truly reflect the changes, the Color Picker tool still shows exactly the same color as before applying the Curve Tool. I have to export the image and reload it into GIMP before I get the actual colors in the Color Picker tool. Am I missing something, or is this a bug?

Thanks a lot for the response. So this looks like a consequence of the newly added feature that allows you to e.g. modify fx operations you performed on a layer without having to undo everything you did after applying the fx function. I like that. Also it allows you to perform the same fx functions on other layers which is nice. Maybe it is an idea to set the "Enable Merge filter" defaut to ON, to avoid this "problem" for the not so experienced users.

[rich2005]

As far as I know, the Enable merge is persistent and when set remains on. However, it is not global and you have to set it for each tool where it is available.
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Edit Quote ".....to avoid this "problem" for the not so experienced users"
In my opinion it should be more that just the merge option. There should be "beginners" UI with several of the tabs removed, tabs locked, the grey theme as default. Think what Gimp 2.8 looked like when first introduced.
It is possible to set Gimp up the way you want, and turn off the "Save on Exit" functions. That way Gimp reverts when restarted. For example, how many new users close the tool options and wonder where they have gone, You see that over-and-over.

Of course, never going to happen, too many want Gimp to mimic PS.

[Scallact]

Yes, the "Sample merged" option does pick the visible color. But it seems there is actually a bug: it only works when you have at least two layers. With just one layer and a filter applied to it, the option doesn't apply.

[laren99]

Hi I'm using color picker to check image values before printing, and like the OP I had problems with values not updating when a filter was applied.
Thanks for the tip to merge the active filters down, that works.
But I feel the solution should be to make the sample merged option work without unnecessary opening a second image layer below.[url=https://www.gimp-forum.net/images/smilies/biggrin.png][/url]

[CmykStudent_]

This was brought up after the first release with NDE filters. I think I still have an open merge request that makes the color picker sample from the layer + filters instead of just the layer.

If I remember correctly, the concern was that some people might want to sample the raw pixels instead of the layer + filters. There were some UX discussions about how to handle that. I'll try to dig up the merge request and see if I can implement whatever the requested design was.