How to colorize with specific color / change color without losing details on the edges

Question

I have a very simple image that consists of 1 color and text cut out of it (the text is transparent).

I now want to change the colored part to a different color, but on the edges the color is not completely solid as you can see.

When I use "bucket fill", it just fills everything with a solid color.

When I use "Colorize" it looks perfect, but then I can't choose a specific hexcode.

When I use "Colorify" it looks perfect too and I can choose a hex code, but then it just adds the new color on top of it.

Is there a way to repalce this green with a different specific hex code and keep the details?

Answer 1

Change the colour of a layer with an alpha channel or partial transparency

This can be achieved using channels, at least in the simple case:

1. In the Channels tab (next to Layers tab here), right-click on the alpha channel
2. Select channel to selection
3. Fill with desired colour (I used Ctrl+, - Fill with FG colour in the demo below)

(Demo of the above on a small sample I created using GIMP 2.10.6)

Note

At step 2, once you've selected the alpha channel; if you zoom in on 'faint' high alpha pixels they may seem as though they are not selected, but they are.