How do I change a specific colour in a specific layer?

[AnyOldBiscuit]

I want to change the colour of drawn lines from one shade of green to another. All the green lines are in one layer, except for a few which are in another layer (I also want to change these ones). I have tried the bucket fill tool, but it ends up filling in the edges so it no longer has anti-aliasing, end, as a consequence, also fills small gaps. Somehow, the bucket fill tool worked fine to change colour when I tested it on a blank canvas. How do I change the colour without affecting the entire image? I only want to change the pixels that make up the lines.

[denzjos]

Try 'Colours / Hue-Saturation' , tick the color green (G) and use the hue slider.

   

[Ofnuts]

The best way is to extract the lines from the background: in other words, have the lines on a transparent layer, and the backrgound layer under it. This lets you have partially transparent pixels on the edges of the lines (that re important for smooth lines).

The you set the alpha-lock on the lines layer so that painting will keep the opacity of the pixels, and these 'smoothing" pixels will receive the new color but remain partially transparent.

If your lines are currently on a uniform background, you can extract them using "Color>Color to alpha" to make the background transparent.

For more information see: https://www.gimp-forum.net/Thread-Backgr...r-graphics

[migf1]

(06-12-2020, 01:41 PM)AnyOldBiscuit Wrote: I want to change the colour of drawn lines from one shade of green to another. All the green lines are in one layer, except for a few which are in another layer (I also want to change these ones). I have tried the bucket fill tool, but it ends up filling in the edges so it no longer has anti-aliasing, end, as a consequence, also fills small gaps. Somehow, the bucket fill tool worked fine to change colour when I tested it on a blank canvas. How do I change the colour without affecting the entire image? I only want to change the pixels that make up the lines.

You can also try to Lock the Alpha Channel before using the Bucket Filling. In 2.10.20, it is the last one of the 3 Lock icon, right below the layer opacity slider: http://prntscr.com/sz46ct

[rich2005]

(06-13-2020, 05:07 PM)migf1 Wrote: You can also try to Lock the Alpha Channel before using the Bucket Filling

Yeah, all depends if the lines are on a transparent layer. From a similar post a couple of days ago https://i.imgur.com/39kVCLB.mp4

Quote: All the green lines are in one layer, except for a few which are in another layer (I also want to change these ones)...snip...I only want to change the pixels that make up the lines.

For the 'other layer' Again providing it is lines on a transparent layer, make a selection of what needs changing, then as above.

[AnyOldBiscuit]

All the lines I want to change are in transparent layers with other lines of the same colour. How do I change the colour? The thread https://www.gimp-forum.net/Thread-Backgr...r-graphics doesn't seem relevant to that.

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Problem solved. I just needed to lock the alpha channel then bucket fill.