Look how light the tooltip text is here. It's near impossible to read because it's printed with white text on a nearly white background.

In Kubuntu 16.10 I can't even read the tooltip dialogs in the GIMP image editor because they are too light to read. See the image here for an example of what I'm talking about.

Here is how to fix the problem of too light tooltips in the GIMP

Thanks to this Kubuntu forum thread, I now know how to fix the tooltips so that they are readable. Read on and I'll show you how.

Step 1: Close the GIMP application.

After clicking on that big "K" at the bottom of the screen, start typing "System Settings" until you see the "System Settings" menu item, and then click on it.

Step 2: Open up the "System Settings" in Kubuntu

To do that:

  1. click on the Application Launcher, which is the button with a letter "K" on it located on the panel.
  2. Start typing "System Settings" in the search until the "System Settings" menu item appears.
  3. Click on the "System Settings" menu item to open the "System Settings" application
Click on "Application Style"
Click on "GNOME Application Style (GTK)"
Select "oxygen-gtk" as the GTK2 Theme
Remember to click "Apply"!

Step 3: Change the Application Style

  1. From the System Settings program, click on the "Application Style" item.
  2. Then click on "GNOME Application Style (GTK)
  3. Locate the section titled "GTK Themes" and where it says "Select a GTK2 Theme, set it to "oxygen-gtk" from the dropdown menu.
  4. click "Apply"
Now my tooltips look great. I no longer have to strain to read white text on a nearly white background!

The result

Now if everything worked as planned you should have tooltips that are easy to read. As you can see in the picture here, after performing the steps listed above I have easy to read tool tips in white text on a contrasting dark grey background. 

As a bonus, the steps that were taken to fix the too light tooltips in the GIMP also fixed the tooltip contrast in other apps like Kdenlive (the video editor) and Shutter (an excellent screenshot tool).