How to Change the Underline Color for Word Spellcheck

On Windows, the spellcheck in Word usually underlines errors with a blue or red color by default.

In Windows 365-enabled licenses, you might also get other options such as purple for contextual edits. 



The default colors are all hardcoded into the program but it’s possible to change the color of spellcheck underlines in Word.

In this article, I’ll walk you through how you can the color of spellcheck underlines in Word with the use of Registry.

Word Spellcheck: Change Underline Color with the Registry Editor Step-by-Step

First, you need to ensure that you have the administrator access to your system to change the registry. If you are on a system with a guest account or work user, you might need to ask your IT to enable the registry editor for you.

Step 1. Hit “Win + R” on the keyboard to open the Run utility.

Step 2. Enter “regedit” and click on “Ok” or hit “Enter.” Choose “Yes” on the User Account Control access when prompted.

Step 3. Go to the following address in the Registry Editor:

Computer\HKEY_CURRENT_USER\Software\Microsoft\Shared Tools\Proofing Tools

You can either click manually through each folder in the path, or drag over the entire address in the address bar, then paste in the path from above.

Step 4. In the pane on the right, check if you have “SpellingWavyUnderlineColor” as an entry. If you do, double-click on it. If you don’t, right-click on an empty space in the pane and select “New” then “DWORD Value.” Enter “SpellingWavyUnderlineColor” as the name of the value.

Step 5. Double-click on the value, then select “Hexadecimal” for the base. In the “value data” textbox, enter the RGB of the color you need preceded by 00 (for example, 00FF0000 is red). The editor should accept both lowercase and uppercase letters.

Step 6. Repeat Steps 4 and 5 for the following entries:

• SpellingWavyUnderlineColor (already done as the first part) – underlines typing issues.
• GrammarWavyUnderlineColor – underlines grammar errors.
• ContextualSpellingWavyUnderlineColor – underlines contextual spelling differences (there > their)
• SmartTagUnderlineColor – available in older versions of Word for smart tags. These are typically nonexistent on Word 2019 and later, so you might not need them at all.

Step 7. Exit the Registry Editor, which automatically saves your progress, then restart the PC.

What Colors to Change Color of Spellcheck Underlines in Word

Technically, since the registry uses RGB color coding, you can use pretty much any color that has an associated RGB (red-green-blue) hexadecimal. You can refer to the following table for some common colors, alongside their color codes.

You can also use online sources to get the color codes in RGB. Whichever option you use, make sure to append two zeroes (00) before the color’s RGB values in hexadecimal to use for the Registry Editor. This denotes transparency for the ARGB system, which needs to default to 0.

Alternatively, you can use additional numbers, with the 00 > FF scaling in transparency. This can produce odd results, as “80” converts to 50.2% transparency (since 80 converts to 128 which is slightly more than half of 255, the max value of two hexadecimal digits). If the color picker uses RGBA, change the code accordingly.