http://product.corel.com/help/CorelDRAW/540223850/Main/JP/Documentation/wwhelp/wwhimpl/common/html/wwhelp.htm#context=CorelDRAW&file=CorelDRAW-Choosing-colors.html
一部のプログラムでは、カラー パレットは「スウォッチ パレット」と呼ばれています。

I don't think we need absolutely all of the words/terms used in Photoshop/Illustrator, but there's a certain subset that's commonly used outside of the confines of their interfaces, and thus useful. Any word used by either or both of these apps will also be used by other similar apps as well as a general rule (GIMP, CorelDRAW, etc.). In this particular case, I think this word would have been worth including even if the word wasn't used outside of these apps precisely because we didn't have any coverage whatsoever for "スウォッチ", anybody coming across it might have a hard time realizing it's a rendition of "swatch".

In this case it's not an issue as the word is used with its original English meaning(s), but if it weren't, "swatch" would be insufficient because none of the dictionary definitions of "swatch" would apply to スウォッチ.
I'm not convinced we need to add terms that are only used in a particular application, even if it's an industry standard. We don't have separate Photoshop-specific senses on other entries. But in any case, there are probably very few (non-compound) words in Photoshop, Illustrator, etc. that aren't already entries in jmdict.

usage on grpahic.jp, a major on-demand/offset printer:
https://www.graphic.jp/customer/faq/answer/100644
伝統色などスウォッチカラーにない特色はどのように設定すればよいか知りたい
https://www.graphic.jp/download/templates/146
オンデマンド・メタリックカラースウォッチテンプレート
オンデマンドにてメタリックカラーをご利用いただく際のスウォッチ（Illustrator形式）を無料でダウンロードいただけます。


non-comp use:
https://www.cosme.net/beautist/article/2584329
【全24色スウォッチ公開】シュウ ウエムラの大人気ファンデ、色選びのコツを教えます！

https://www.cosme.net/beautist/article/2607414
【スウォッチあり】失敗しない！ファンデのカラー選びのコツ★うるおいに満ちたツヤ肌ベースメイクの仕込み方をご紹介
今回は、スウォッチとともにカラー選びのコツをご紹介いたします。ぜひ参考にしてみてください(^^)

https://ais-ais.co.jp/swha.html
スウォッチ - HA
生地が大きくて見やすい、人気の色見本です。

https://meeco.mistore.jp/contents/magazine/column/20220216_02.html
＜ローラ メルシエ＞ブラッシュ カラー インフュージョン
【チーク全色スウォッチ】

https://irodori-store.shop/items/5a2f416692d75f5d050000ef
スウォッチ（色見本）

I think it's better just as "swatch" as it's evidently used outside of software too.

I don't agree that we need to explain that this or similar words might be specific to Photoshop/Illustrator. Anybody dealing with anything printing or design-related can come across these words on the web and elsewhere. That they might or might not be specific to the software that everybody in these fields are using doesn't seem all that relevant to me.

@@ -9,2 +9 @@
-<field>&comp;</field>
-<gloss>swatch (color, tint, etc.)</gloss>
+<gloss>swatch</gloss>

But this doesn't explain that it's an Illustrator/Photoshop term. It's not really computing terminology.
Unless it's become generic, I don't think it should be an entry. Surely Illustrator and Photoshop use hundreds of words with application-specific meanings.

Maybe this. The main "swatch" I have encountered is in fabric samples, but that doesn't seem to be associated with スウォッチ'

@@ -10 +10 @@
-<gloss>swatch</gloss>
+<gloss>swatch (color, tint, etc.)</gloss>