How to change color of multiple text objects at once

Requires script-fu Color Overlay script for Gimp.

Create a layer group, add your text layers to it.

Select group layer (top of 'tree'), Script-Fu > Layer Effects > Color Overlay (select color). It will change all the text layer colors and does it by adding a new overlay layer. If you don't like it, you can remove the layer (or change opacity etc or start over. Nice solution. You're welcome :-)

I’m using GIMP and I guess I just figured it out how to put color on one group of text layers:

1. Simply put them in one layer group.
2. Make a new layer in that group.
3. Here is the twist: Mark that layer as transparency.
4. On that layer, right-click and select alpha to selection.
5. Use the bucket tool to change to your desired color.

Using a layer group:

• Create you text layers using neutral gray (127,127,127)
• Create a layer group
• Move all you text layers to the layer group
• Add a new layer at the top of the group, and set it to "Color" mode
• You can then color all you text layers (and only them) by bucket-filling that layer with the required color
• You can of course use multiple groups

Having an opaque layer above your text layers will make them difficult to move (the Move tool will pick the color layer). Just make the color layer invisible temporarily.

Note: if starting with black text, use Lighten only mode on the color layer.

In my opinion current Gimp versions (2.8) doesn't allow multiple layers selection, you can group or chain them (see also this question), but this is not the same thing, and you can't change at once the color of grouped of chained text boxes.

A fast way to change is the following:

1. Select a text layer

2.-3. Drag the color from the Toolbox color and drop it onto the image. It should change the color of the selected Textbox. Note: this method doesn't work if you have already manually changed the color of the text by selecting some characters or the whole text using the text tool.

4. Repeat previous steps until done.

See also here.

Its simple.
Select (shift Select) all your text layers that needs a color change.
Now go to the color picker select your desired color.
You should see the color change reflected on all your text layers.