Overriding Intellisense colors in Visual Studio 2015

@karoberts answer is good although with the Visual Studio 2015 Color Theme Editor already installed I had to

• Update the Editor Tooltip -> Plain Text -> Foreground to be bright, and the Environment -> ToolTip to be dark
• apply the theme
• restart Visual Studio (otherwise it wouldn't take the background)

But exporting/importing as in @karoberts answer was not necessary.

Try this
tools > options > fonts and colors > show settings for "Enviroment" > tooltip > item background

I have this same issue, as I use a dark blue background with light text.

What I did was use this add-on:

https://visualstudiogallery.msdn.microsoft.com/6f4b51b6-5c6b-4a81-9cb5-f2daa560430b

Then copy the theme you are currently using, but do not switch to it yet (if you want to keep your current font / color settings).

I then exported my "Font and Color" settings, opened the generated file, and removed the "Theme" XML element completely.

You can then switch to the new copied theme and re-import your color settings from the file just created using "Import and Export Settings".

Then go to the theme editor add-on under Tools > Customize Colors. Edit your theme. Select the "Show All Elements" option and search for "tooltip" in the *.theme file. Update the Editor Tooltip -> Plain Text -> Foreground to be bright, and the Environment -> ToolTip to be dark.

It isn't a perfect solution, but it is usable until they fix it.