Add support for `diff.plus` and `diff.minus` highlight captures (#45459)

Bret Comnes , Finn Evers , and MrSubidubi created 

- Update diff in highlights.scm to use semantic @diff.plus and
@diff.minus tokens
- Add diff.plus, diff.minus tokens to fallback theme
- Add diff syntax tokens to all official themes (One, Gruvbox, Ayu)

This fixes the issue where diff files showed inverted colors (additions
in purple/blue, deletions in green) by using proper semantic tokens
instead of @string and @keyword.

Related discussion in https://github.com/zed-industries/zed/issues/34057
(thought there might be second issue in that issue)

Release Notes:

- Added support for diff.plus, diff.minus and diff.deleta theme
selectors in the diff syntax grammar. Previously diff.plus was mapped to
@string and diff.minus was mapped to @keyword.

*Before:*

<img width="689" height="566" alt="Screenshot 2025-12-20 at 10 58 34 AM"
src="https://github.com/user-attachments/assets/b7ae4428-2011-4ec2-a803-7e30599e1715"
/>

*After:*

<img width="659" height="548" alt="Screenshot 2025-12-20 at 10 58 30 AM"
src="https://github.com/user-attachments/assets/02df31b5-1f1a-40af-adf0-1ac34457cdd4"
/>

*Before:*

<img width="650" height="545" alt="Screenshot 2025-12-20 at 10 58 16 AM"
src="https://github.com/user-attachments/assets/78b348bd-1b91-478b-a850-8e526adcfb3c"
/>

*After:*

<img width="627" height="563" alt="Screenshot 2025-12-20 at 10 58 21 AM"
src="https://github.com/user-attachments/assets/1176d626-563f-455a-9902-137f646eb8f2"
/>

*Before:*

<img width="628" height="550" alt="Screenshot 2025-12-20 at 10 58 06 AM"
src="https://github.com/user-attachments/assets/d819f478-bb2d-4afd-8013-c4e1a2f64dfe"
/>

*After:*

<img width="643" height="642" alt="Screenshot 2025-12-20 at 10 56 00 AM"
src="https://github.com/user-attachments/assets/e0f03549-77ed-4a47-b1da-239b519b90f4"
/>

---------

Co-authored-by: Finn Evers <finn.evers@outlook.de>
Co-authored-by: MrSubidubi <finn@zed.dev>

Change summary

assets/themes/ayu/ayu.json              | 30 +++++++++++++
assets/themes/gruvbox/gruvbox.json      | 60 +++++++++++++++++++++++++++
assets/themes/one/one.json              | 20 +++++++++
crates/grammars/src/diff/highlights.scm |  6 -
crates/theme/src/fallback_themes.rs     |  2 
5 files changed, 114 insertions(+), 4 deletions(-)

Detailed changes

assets/themes/ayu/ayu.json 🔗 

@@ -391,6 +391,16 @@
             "color": "#5ac1feff",
             "font_style": null,
             "font_weight": null
+          },
+          "diff.plus": {
+            "color": "#aad94cff",
+            "font_style": null,
+            "font_weight": null
+          },
+          "diff.minus": {
+            "color": "#f07178ff",
+            "font_style": null,
+            "font_weight": null
           }
         }
       }
@@ -783,6 +793,16 @@
             "color": "#3b9ee5ff",
             "font_style": null,
             "font_weight": null
+          },
+          "diff.plus": {
+            "color": "#6cbf43ff",
+            "font_style": null,
+            "font_weight": null
+          },
+          "diff.minus": {
+            "color": "#ff6666ff",
+            "font_style": null,
+            "font_weight": null
           }
         }
       }
@@ -1175,6 +1195,16 @@
             "color": "#72cffeff",
             "font_style": null,
             "font_weight": null
+          },
+          "diff.plus": {
+            "color": "#aad94cff",
+            "font_style": null,
+            "font_weight": null
+          },
+          "diff.minus": {
+            "color": "#f07178ff",
+            "font_style": null,
+            "font_weight": null
           }
         }
       }

assets/themes/gruvbox/gruvbox.json 🔗 

@@ -406,6 +406,16 @@
             "color": "#83a598ff",
             "font_style": null,
             "font_weight": null
+          },
+          "diff.plus": {
+            "color": "#b8bb26ff",
+            "font_style": null,
+            "font_weight": null
+          },
+          "diff.minus": {
+            "color": "#fb4934ff",
+            "font_style": null,
+            "font_weight": null
           }
         }
       }
@@ -813,6 +823,16 @@
             "color": "#83a598ff",
             "font_style": null,
             "font_weight": null
+          },
+          "diff.plus": {
+            "color": "#b8bb26ff",
+            "font_style": null,
+            "font_weight": null
+          },
+          "diff.minus": {
+            "color": "#fb4934ff",
+            "font_style": null,
+            "font_weight": null
           }
         }
       }
@@ -1220,6 +1240,16 @@
             "color": "#83a598ff",
             "font_style": null,
             "font_weight": null
+          },
+          "diff.plus": {
+            "color": "#b8bb26ff",
+            "font_style": null,
+            "font_weight": null
+          },
+          "diff.minus": {
+            "color": "#fb4934ff",
+            "font_style": null,
+            "font_weight": null
           }
         }
       }
@@ -1627,6 +1657,16 @@
             "color": "#0b6678ff",
             "font_style": null,
             "font_weight": null
+          },
+          "diff.plus": {
+            "color": "#79740eff",
+            "font_style": null,
+            "font_weight": null
+          },
+          "diff.minus": {
+            "color": "#9d0006ff",
+            "font_style": null,
+            "font_weight": null
           }
         }
       }
@@ -2034,6 +2074,16 @@
             "color": "#0b6678ff",
             "font_style": null,
             "font_weight": null
+          },
+          "diff.plus": {
+            "color": "#79740eff",
+            "font_style": null,
+            "font_weight": null
+          },
+          "diff.minus": {
+            "color": "#9d0006ff",
+            "font_style": null,
+            "font_weight": null
           }
         }
       }
@@ -2441,6 +2491,16 @@
             "color": "#0b6678ff",
             "font_style": null,
             "font_weight": null
+          },
+          "diff.plus": {
+            "color": "#79740eff",
+            "font_style": null,
+            "font_weight": null
+          },
+          "diff.minus": {
+            "color": "#9d0006ff",
+            "font_style": null,
+            "font_weight": null
           }
         }
       }

assets/themes/one/one.json 🔗 

@@ -403,6 +403,16 @@
             "color": "#73ade9ff",
             "font_style": null,
             "font_weight": null
+          },
+          "diff.plus": {
+            "color": "#98c379ff",
+            "font_style": null,
+            "font_weight": null
+          },
+          "diff.minus": {
+            "color": "#e06c75ff",
+            "font_style": null,
+            "font_weight": null
           }
         }
       }
@@ -805,6 +815,16 @@
             "color": "#5b79e3ff",
             "font_style": null,
             "font_weight": null
+          },
+          "diff.plus": {
+            "color": "#50a14fff",
+            "font_style": null,
+            "font_weight": null
+          },
+          "diff.minus": {
+            "color": "#e45649ff",
+            "font_style": null,
+            "font_weight": null
           }
         }
       }

crates/grammars/src/diff/highlights.scm 🔗 

@@ -3,15 +3,13 @@
 [
   (addition)
   (new_file)
-] @string
+] @string @diff.plus
 
-; TODO: This should eventually be `@diff.plus` with a fallback of `@string`
 [
   (deletion)
   (old_file)
-] @keyword
+] @keyword @diff.minus
 
-; TODO: This should eventually be `@diff.minus` with a fallback of `@keyword`
 (commit) @constant
 
 (location) @attribute

crates/theme/src/fallback_themes.rs 🔗 

@@ -377,6 +377,8 @@ pub(crate) fn zed_default_dark() -> Theme {
                 ("variable".into(), HighlightStyle::default()),
                 ("variable.special".into(), red.into()),
                 ("variant".into(), HighlightStyle::default()),
+                ("diff.plus".into(), green.into()),
+                ("diff.minus".into(), red.into()),
             ])),
         },
     }