> For the complete documentation index, see [llms.txt](https://docs.sevenpens.com/drawtab/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.sevenpens.com/drawtab/guides/pen-displays/color-tint-on-edges.md).

# Color tint on edges of display

## Overview

Some pen displays exhibit a color tint (purple/lilac or yellow/orange) at the edges of the display.

## Appearance

* The tint is NOT pixelated or rough. It has a very smooth look.
* It is often seen on all four edges. I can't think of any examples on only three or fewer edges.
* Can be very faint.
* You may notice it only when colors on the screen are bright.
* May appear when you first use your tablet, or develop much later. Out of 30+ pen displays, I have one display (Huion Kamvas 22 Plus) that developed a slight purple edge tint 3+ years after I bought it.

NOTE: The tint is greatly exaggerated in these diagrams.

<figure><img src="https://1457921496-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNde0PQIvNcFZNVxuTO0G%2Fuploads%2FsRaG7vLPhsvgWUrKh9WM%2FSlide_20260602_113722.jpg?alt=media&amp;token=ab72b59a-30a4-4e7e-9c33-684aae6a84a7" alt=""><figcaption></figcaption></figure>

In practice, the effect is usually VERY subtle - as you can see below.

<figure><img src="https://1457921496-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNde0PQIvNcFZNVxuTO0G%2Fuploads%2FZU1bsWV2fqqjlZnlLzdW%2FSlide_20260602_113822.jpg?alt=media&amp;token=d163e737-d82d-4683-83d6-4fffe6c0ab33" alt=""><figcaption></figcaption></figure>

## Examples

<figure><img src="https://1457921496-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNde0PQIvNcFZNVxuTO0G%2Fuploads%2FBVtlk5guuSlnD81wQ5Yv%2Fpwjk86u72hda1.jpg?alt=media&amp;token=680f1b1a-bea9-490c-b79a-09afa2fd44d0" alt=""><figcaption><p>Notice that the purple tint is visible even on a pure white background - it slightly darkens the white region</p></figcaption></figure>

## When it appears

This effect can be visible the first time you use your pen display, or it can show up after you've been using the pen display for a long time.

## Compared to backlight bleed

Unlike backlight bleed, the tint is often visible even on a very bright or pure white background.

## Causes

Based on what I have read, the cause is due to an issue with laminated displays (see: [Lamination](/drawtab/guides/pen-displays/lamination.md)).

My leading theory as to the specific cause is an issue with the polarizer layer in the display. When there is a polarizer failure it can appear in very different ways visually - sometimes very harsh effects and sometimes much more subtle (as in this case).

The polarizer might

* delaminate (separate from the rest of the display)
* be oriented incorrectly
* be damaged by heat
* be damaged by pressure

Laminated displays have a layer of optically clear adhesive (OCA) between the glass and the display. This might also contribute to or be the source of the problem.

## How often it occurs

Overall it is uncommon.

Of the 30+ pen displays I own, it is present in none of the laminated display devices I have.

## Manufacturer pages

* Huion: <https://support.huion.com/en/support/solutions/articles/44002336996-how-to-adjust-color-difference-on-the-edge-of-your-tablet-by-importing-the-new-color-gamut-file-windo>

## Links

* [**r/huion - Purple edges on my kanvas 24 plus??**](https://www.reddit.com/r/huion/comments/10i3ftd/purple_edges_on_my_kanvas_24_plus/) 2023-01-21
* [**r/huion - Bought a Kamvas Pro 16 2.5K – local retailer says it comes with purple edges like this, and isn’t faulty – is that really true?**](https://www.reddit.com/r/huion/comments/vo3o5m/bought_a_kamvas_pro_16_25k_local_retailer_says_it/) 2022-06-30
* [**r/4kTV - Sony Purple Edges**](https://www.reddit.com/r/4kTV/comments/zt6kf2/sony_purple_edges/) 2022-12-22