Add support for macOS accent colors

README.md

@@ -41,6 +41,12 @@ By default, `folderify` uses your system's current light/dark mode. Use `--color
 folderify --color-scheme dark mask.png
 ```
 
+On macOS Tahoe, `folderify` uses your current system icon theme color by default. Use `--folder-color` to override it:
+
+```shell
+folderify --macOS 26 --folder-color auto mask.png
+```
+
 Note:
 
 - There is currently no simple way to set an icon that will automatically switch between light and dark when you switch the entire OS. You can only assign one version of an icon to a folder.
@@ -168,6 +174,14 @@ Options:
           [default: auto]
           [possible values: auto, light, dark]
 
+      --folder-color <FOLDER_COLOR>
+          Tahoe folder color. `auto` matches the current Tahoe icon theme color,
+          `multicolor` keeps the default macOS folder look, and the tinted
+          variants use Tahoe's tinted folder rendering
+
+          [default: auto]
+          [possible values: auto, multicolor, blue, graphite, green, orange, pink, purple, red, yellow]
+
       --no-trim
           Don't trim margins from the mask.
           By default (i.e. without this flag), transparent margins are trimmed from all 4 sides.

src/args.rs

@@ -58,6 +58,12 @@ struct FolderifyArgs {
     #[clap(long, value_enum, default_value_t = ColorSchemeOrAuto::Auto)]
     color_scheme: ColorSchemeOrAuto,
 
+    /// Tahoe folder color. `auto` matches the current Tahoe icon theme color,
+    /// `multicolor` keeps the default macOS folder look, and the tinted
+    /// variants use Tahoe's tinted folder rendering.
+    #[clap(long, value_enum, default_value_t = FolderColorOrAuto::Auto)]
+    folder_color: FolderColorOrAuto,
+
     /// Don't trim margins from the mask.
     /// By default (i.e. without this flag), transparent margins are trimmed from all 4 sides.
     #[clap(long, verbatim_doc_comment)]
@@ -94,6 +100,19 @@ pub enum ColorScheme {
     Dark,
 }
 
+#[derive(ValueEnum, Clone, Debug, PartialEq, Copy)]
+pub enum FolderColor {
+    Multicolor,
+    Blue,
+    Graphite,
+    Green,
+    Orange,
+    Pink,
+    Purple,
+    Red,
+    Yellow,
+}
+
 #[derive(ValueEnum, Clone, Debug, PartialEq, Copy)]
 pub enum Badge {
     Alias,
@@ -113,6 +132,42 @@ impl Display for ColorScheme {
     }
 }
 
+impl FolderColor {
+    pub fn as_str(&self) -> &'static str {
+        match self {
+            Self::Multicolor => "multicolor",
+            Self::Blue => "blue",
+            Self::Graphite => "graphite",
+            Self::Green => "green",
+            Self::Orange => "orange",
+            Self::Pink => "pink",
+            Self::Purple => "purple",
+            Self::Red => "red",
+            Self::Yellow => "yellow",
+        }
+    }
+}
+
+impl Display for FolderColor {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.as_str())
+    }
+}
+
+#[derive(ValueEnum, Clone, Debug, PartialEq, Copy)]
+enum FolderColorOrAuto {
+    Auto,
+    Multicolor,
+    Blue,
+    Graphite,
+    Green,
+    Orange,
+    Pink,
+    Purple,
+    Red,
+    Yellow,
+}
+
 #[derive(ValueEnum, Clone, Debug, PartialEq)]
 enum ColorSchemeOrAuto {
     Auto,
@@ -141,6 +196,7 @@ enum SetIconUsingOrAuto {
 pub struct Options {
     pub mask_path: PathBuf,
     pub color_scheme: ColorScheme,
+    pub folder_color: FolderColor,
     pub no_trim: bool,
     pub target: Option<PathBuf>,
     pub folder_style: FolderStyle,
@@ -259,9 +315,21 @@ pub fn get_options() -> Options {
         Some(SetIconUsingOrAuto::Fileicon) => SetIconUsing::Fileicon,
         _ => SetIconUsing::Osascript,
     };
+    if folder_style != FolderStyle::Tahoe
+        && !matches!(
+            args.folder_color,
+            FolderColorOrAuto::Auto | FolderColorOrAuto::Multicolor
+        )
+    {
+        eprintln!(
+            "Folder tint variants are only available for Tahoe. \
+Ignoring `--folder-color`."
+        );
+    }
     Options {
         mask_path: mask,
         color_scheme: map_color_scheme_auto(args.color_scheme, folder_style),
+        folder_color: normalized_folder_color(folder_style, args.folder_color),
         no_trim: args.no_trim,
         target: args.target,
         folder_style,
@@ -277,6 +345,83 @@ pub fn get_options() -> Options {
     }
 }
 
+fn normalized_folder_color(
+    folder_style: FolderStyle,
+    folder_color: FolderColorOrAuto,
+) -> FolderColor {
+    if folder_style != FolderStyle::Tahoe {
+        return FolderColor::Multicolor;
+    }
+
+    match folder_color {
+        FolderColorOrAuto::Auto => current_system_folder_color(),
+        FolderColorOrAuto::Multicolor => FolderColor::Multicolor,
+        FolderColorOrAuto::Blue => FolderColor::Blue,
+        FolderColorOrAuto::Graphite => FolderColor::Graphite,
+        FolderColorOrAuto::Green => FolderColor::Green,
+        FolderColorOrAuto::Orange => FolderColor::Orange,
+        FolderColorOrAuto::Pink => FolderColor::Pink,
+        FolderColorOrAuto::Purple => FolderColor::Purple,
+        FolderColorOrAuto::Red => FolderColor::Red,
+        FolderColorOrAuto::Yellow => FolderColor::Yellow,
+    }
+}
+
+fn current_system_folder_color() -> FolderColor {
+    let icon_appearance_theme = read_global_default("AppleIconAppearanceTheme");
+    if !icon_appearance_theme
+        .as_deref()
+        .is_some_and(|theme| theme.starts_with("Tinted"))
+    {
+        return FolderColor::Multicolor;
+    }
+
+    let Some(accent_color_string) = read_global_default("AppleAccentColor") else {
+        eprintln!("Could not compute auto folder color. Assuming multicolor.");
+        return FolderColor::Multicolor;
+    };
+
+    let Some(folder_color) = parse_system_accent_color(&accent_color_string) else {
+        eprintln!(
+            "Could not map the system accent color to a Tahoe folder tint. \
+Assuming multicolor."
+        );
+        return FolderColor::Multicolor;
+    };
+
+    folder_color
+}
+
+fn read_global_default(key: &str) -> Option<String> {
+    let output = Command::new("/usr/bin/env")
+        .args(["defaults", "read", "-g", key])
+        .output()
+        .ok()?;
+    if !output.status.success() {
+        return None;
+    }
+
+    let stdout = from_utf8(&output.stdout).ok()?.trim().to_owned();
+    if stdout.is_empty() {
+        return None;
+    }
+    Some(stdout)
+}
+
+fn parse_system_accent_color(accent_color: &str) -> Option<FolderColor> {
+    match accent_color.trim().parse::<i32>().ok()? {
+        -1 => Some(FolderColor::Graphite),
+        0 => Some(FolderColor::Red),
+        1 => Some(FolderColor::Orange),
+        2 => Some(FolderColor::Yellow),
+        3 => Some(FolderColor::Green),
+        4 => Some(FolderColor::Blue),
+        5 => Some(FolderColor::Purple),
+        6 => Some(FolderColor::Pink),
+        _ => None,
+    }
+}
+
 fn map_color_scheme_auto(
     color_scheme: ColorSchemeOrAuto,
     folder_style: FolderStyle,
@@ -332,7 +477,14 @@ fn current_macOS_version() -> String {
 
 #[cfg(test)]
 mod tests {
-    use crate::args::FolderifyArgs;
+    use crate::args::{
+        normalized_folder_color,
+        parse_system_accent_color,
+        FolderColor,
+        FolderColorOrAuto,
+        FolderStyle,
+        FolderifyArgs,
+    };
 
     // https://docs.rs/clap/latest/clap/_derive/_tutorial/index.html#testing
     #[test]
@@ -341,4 +493,41 @@ mod tests {
 
         FolderifyArgs::command().debug_assert();
     }
+
+    #[test]
+    fn test_system_accent_color_mapping() {
+        assert_eq!(parse_system_accent_color("-1"), Some(FolderColor::Graphite));
+        assert_eq!(parse_system_accent_color("0"), Some(FolderColor::Red));
+        assert_eq!(parse_system_accent_color("1"), Some(FolderColor::Orange));
+        assert_eq!(parse_system_accent_color("2"), Some(FolderColor::Yellow));
+        assert_eq!(parse_system_accent_color("3"), Some(FolderColor::Green));
+        assert_eq!(parse_system_accent_color("4"), Some(FolderColor::Blue));
+        assert_eq!(parse_system_accent_color("5"), Some(FolderColor::Purple));
+        assert_eq!(parse_system_accent_color("6"), Some(FolderColor::Pink));
+        assert_eq!(parse_system_accent_color("99"), None);
+    }
+
+    #[test]
+    fn test_non_tahoe_folder_color_is_always_multicolor() {
+        assert_eq!(
+            normalized_folder_color(FolderStyle::BigSur, FolderColorOrAuto::Auto),
+            FolderColor::Multicolor
+        );
+        assert_eq!(
+            normalized_folder_color(FolderStyle::BigSur, FolderColorOrAuto::Purple),
+            FolderColor::Multicolor
+        );
+    }
+
+    #[test]
+    fn test_tahoe_explicit_folder_color_is_preserved() {
+        assert_eq!(
+            normalized_folder_color(FolderStyle::Tahoe, FolderColorOrAuto::Blue),
+            FolderColor::Blue
+        );
+        assert_eq!(
+            normalized_folder_color(FolderStyle::Tahoe, FolderColorOrAuto::Purple),
+            FolderColor::Purple
+        );
+    }
 }