I'm using Gimp 2.18 on my Mac (High Sierra). I want to change the background color on my canvas from white to #696969. I was trying to follow the tutorial here --
https://www.gimp.org/tutorials/Changing_Background_Color_1/ , but when I go to "Filters", I don't see a "Colors" option within it. Mine has "Repeat Color Exchange," "Re-Show Color Exchange," "Recently Used >", "Reset All Filters," etc. But no "Colors" menu.

Any guidance is appreciated, - Dave

This is the problem when you pick up an old how-to dated "Text and images Copyright (C) 2002"

Using Gimp 2.8.x (what is 2.18 ?)

1. Mentioned later in the tutorial but first check that the image is in RGB mode. Use menu Image -> Mode -> RGB

2. The menu to use is now Colours -> Colour to Alpha (step 1) and the default is white so you should not need to colour pick the background colour (step 2 and step 3)

3. Apply and that, it will set an alpha channel and all white becomes transparent (step 4). Note that there might be parts of the image that you want to remain white.

4. Make a new layer, fill with new background colour, move down (as step 5)

rich: www.gimp-forum.net

Thanks, Rich. Ok, I got to step 5 about creating the new layer, but I'm having trouble with the step "(have Foreground set to Red when you do this)". My new layer dialog doesn't look like the one in the tutorial (attached). I can't see where I select a color in that dialog.

Btw, my bad on the version. Its 2.8.18.

Check the screenshots

Click in the Foreground (FG) colour icon (1) that brings up the Change FG Colour dialogue. You do not really need the colour picker in the dialogue, click on a colour or use the sliders.

To use the colour picker. Click on the picker icon (2) and you can pick from anywhere in the dialogue or in the image (3).

Until you get the hang of things, OK to close the dialogue and fix the colour.

You can get a new layer easily using the icon in the layers dialogue (4) Brings up the dialogue as you posted, or use the Layer menu. With FG set that uses the new colour. I prefer a transparent layer and fill it later, up to you.

Move down using the icon (5) in the layers dialogue or use the Layer -> Stack menu

An easy way to fill a layer with colour is click-n-drag from the FG (or BG) icon into the canvas. (6)

rich: www.gimp-forum.net