changing color

[doodle]

I hope I can explain this without being confusing. On the old win paintbrush 3.1, it had a great feature which I always wanted to get. Not sure if possible with Gimp 2.10. Win  PB 3.1 had an eraser feature that would change one color into another color. Example. let's say you have a checkerboard with all green and all blue squares. using that eraser tool dragging it over the checkerboard ONLY the green squares for example will change to another color you want like red the blue would be untouched. Can that be done with gimp 2.10 or even gimp 2.8? If you still don't get what i mean check out this vid at 1:50 into vid it shows what I am looking for.
https://www.youtube.com/watch?v=qk4WYfq_eVg

[dinasset]

Likely you have in mind something more difficult, but if it is that simple (checkerboard with two colours, replace with different two colours), you may:
1. click on "select by color tool" and click on one of the two original colours
(you end up will all squares of that colour selected, usually it's recommended to do "select grow" by 1 pixel)
2. having set your replacing first colour as BG for instance, "fill" the selection with BG
3. repeat steps 1 and 2 for the second colour
But maybe also you like to have just one single step...

[rich2005]

Maybe not in one-go.

Try: 
Add transparency (alpha channel) Layer -> Transparency -> Add alpha channel
Set a paintbrush to suitable size and put the mode to Color-erase set the FG to the color and paint over the area for replace.

   

Next, set the paint brush mode to Behind and the FG to the new colour, and paint over the erased area.

   

edit: Of course, if you are making an image from scratch in Gimp you should use as many layers as is necessary and then changing parts of the design is easy.

[doodle]

(02-15-2020, 04:04 PM)dinasset Wrote: Likely you have in mind something more difficult, but if it is that simple (checkerboard with two colours, replace with different two colours), you may:
1. click on "select by color tool" and click on one of the two original colours
(you end up will all squares of that colour selected, usually it's recommended to do "select grow" by 1 pixel)
2. having set your replacing first colour as BG for instance, "fill" the selection with BG
3. repeat steps 1 and 2 for the second colour
But maybe also you like to have just one single step...

I just used checkerboard for an example basically I want to use eraser and wipe over area with eraser, certain colors will be erased or change to another color.Thanks anyway.

---

(02-15-2020, 04:12 PM)rich2005 Wrote: Maybe not in one-go.

Try: 
Add transparency (alpha channel) Layer -> Transparency -> Add alpha channel
Set a paintbrush to suitable size and put the mode to Color-erase set the FG to the color and paint over the area for replace.



Next, set the paint brush mode to Behind and the FG to the new colour, and paint over the erased area.



edit:  Of course, if you are making an image from scratch in Gimp you should use as many layers as is necessary and then changing parts of the design is easy.

I will try your idea but PB 3.1 was the best to use. I can't use it even with dosbox. Thanks for your suggestion.