diff --git a/Cargo.lock b/Cargo.lock
index 7c72f4b92..8cfa6107a 100644
Binary files a/Cargo.lock and b/Cargo.lock differ
diff --git a/Cargo.toml b/Cargo.toml
index c579773e3..a5a850e09 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -93,6 +93,7 @@ incremental = true
 codegen-units = 256
 
 [workspace.dependencies]
+ansi_colours = "1.2.3"
 anstyle = "1.0.10"
 anyhow = "1.0.94"
 bstr = "1.11.3"
diff --git a/cli/Cargo.toml b/cli/Cargo.toml
index d1c6172bd..1353f815b 100644
--- a/cli/Cargo.toml
+++ b/cli/Cargo.toml
@@ -28,6 +28,7 @@ harness = false
 wasm = ["tree-sitter/wasm", "tree-sitter-loader/wasm"]
 
 [dependencies]
+ansi_colours.workspace = true
 anstyle.workspace = true
 anyhow.workspace = true
 bstr.workspace = true
diff --git a/cli/src/highlight.rs b/cli/src/highlight.rs
index cfdd2f76c..8611374dc 100644
--- a/cli/src/highlight.rs
+++ b/cli/src/highlight.rs
@@ -5,10 +5,11 @@ use std::{
     io::{self, Write as _},
     path::{self, Path, PathBuf},
     str,
-    sync::{atomic::AtomicUsize, Arc, LazyLock},
+    sync::{atomic::AtomicUsize, Arc},
     time::Instant,
 };
 
+use ansi_colours::{ansi256_from_rgb, rgb_from_ansi256};
 use anstyle::{Ansi256Color, AnsiColor, Color, Effects, RgbColor};
 use anyhow::Result;
 use serde::{ser::SerializeMap, Deserialize, Deserializer, Serialize, Serializer};
@@ -44,9 +45,6 @@ pub const HTML_FOOTER: &str = "
 </body>
 ";
 
-static CSS_STYLES_BY_COLOR_ID: LazyLock<Vec<String>> =
-    LazyLock::new(|| serde_json::from_str(include_str!("../vendor/xterm-colors.json")).unwrap());
-
 #[derive(Debug, Default)]
 pub struct Style {
     pub ansi: anstyle::Style,
@@ -224,9 +222,8 @@ fn parse_style(style: &mut Style, json: Value) {
 
     if let Some(Color::Rgb(RgbColor(red, green, blue))) = style.ansi.get_fg_color() {
         if !terminal_supports_truecolor() {
-            style.ansi = style
-                .ansi
-                .fg_color(Some(closest_xterm_color(red, green, blue)));
+            let ansi256 = Color::Ansi256(Ansi256Color(ansi256_from_rgb((red, green, blue))));
+            style.ansi = style.ansi.fg_color(Some(ansi256));
         }
     }
 }
@@ -303,7 +300,8 @@ fn write_color(buffer: &mut String, color: Color) {
             _ => unreachable!(),
         },
         Color::Ansi256(Ansi256Color(n)) => {
-            write!(buffer, "color: {}", CSS_STYLES_BY_COLOR_ID[n as usize]).unwrap();
+            let (r, g, b) = rgb_from_ansi256(n);
+            write!(buffer, "color: #{r:02x}{g:02x}{b:02x}").unwrap();
         }
         Color::Rgb(RgbColor(r, g, b)) => write!(buffer, "color: #{r:02x}{g:02x}{b:02x}").unwrap(),
     }
@@ -314,30 +312,6 @@ fn terminal_supports_truecolor() -> bool {
         .is_ok_and(|truecolor| truecolor == "truecolor" || truecolor == "24bit")
 }
 
-fn closest_xterm_color(red: u8, green: u8, blue: u8) -> Color {
-    use std::cmp::{max, min};
-
-    let colors = CSS_STYLES_BY_COLOR_ID
-        .iter()
-        .enumerate()
-        .map(|(color_id, hex)| (color_id as u8, hex_string_to_rgb(hex).unwrap()));
-
-    // Get the xterm color with the minimum Euclidean distance to the target color
-    // i.e.  distance = √ (r2 - r1)² + (g2 - g1)² + (b2 - b1)²
-    let distances = colors.map(|(color_id, (r, g, b))| {
-        let r_delta = (max(r, red) - min(r, red)) as u32;
-        let g_delta = (max(g, green) - min(g, green)) as u32;
-        let b_delta = (max(b, blue) - min(b, blue)) as u32;
-        let distance = r_delta.pow(2) + g_delta.pow(2) + b_delta.pow(2);
-        // don't need to actually take the square root for the sake of comparison
-        (color_id, distance)
-    });
-
-    Color::Ansi256(Ansi256Color(
-        distances.min_by(|(_, d1), (_, d2)| d1.cmp(d2)).unwrap().0,
-    ))
-}
-
 pub struct HighlightOptions {
     pub theme: Theme,
     pub check: bool,
@@ -518,12 +492,12 @@ mod tests {
         );
         assert_eq!(style.css, Some("color: #26a69a".to_string()));
 
-        // junglegreen gets approximated as darkcyan when the terminal does not support it
+        // junglegreen gets approximated as cadetblue when the terminal does not support it
         env::set_var("COLORTERM", "");
         parse_style(&mut style, Value::String(JUNGLE_GREEN.to_string()));
         assert_eq!(
             style.ansi.get_fg_color(),
-            Some(Color::Ansi256(Ansi256Color(36)))
+            Some(Color::Ansi256(Ansi256Color(72)))
         );
         assert_eq!(style.css, Some("color: #26a69a".to_string()));
 
diff --git a/cli/vendor/xterm-colors.json b/cli/vendor/xterm-colors.json
deleted file mode 100644
index 479944967..000000000
--- a/cli/vendor/xterm-colors.json
+++ /dev/null
@@ -1,258 +0,0 @@
-[
-  "#000000",
-  "#800000",
-  "#008000",
-  "#808000",
-  "#000080",
-  "#800080",
-  "#008080",
-  "#c0c0c0",
-  "#808080",
-  "#ff0000",
-  "#00ff00",
-  "#ffff00",
-  "#0000ff",
-  "#ff00ff",
-  "#00ffff",
-  "#ffffff",
-  "#000000",
-  "#00005f",
-  "#000087",
-  "#0000af",
-  "#0000d7",
-  "#0000ff",
-  "#005f00",
-  "#005f5f",
-  "#005f87",
-  "#005faf",
-  "#005fd7",
-  "#005fff",
-  "#008700",
-  "#00875f",
-  "#008787",
-  "#0087af",
-  "#0087d7",
-  "#0087ff",
-  "#00af00",
-  "#00af5f",
-  "#00af87",
-  "#00afaf",
-  "#00afd7",
-  "#00afff",
-  "#00d700",
-  "#00d75f",
-  "#00d787",
-  "#00d7af",
-  "#00d7d7",
-  "#00d7ff",
-  "#00ff00",
-  "#00ff5f",
-  "#00ff87",
-  "#00ffaf",
-  "#00ffd7",
-  "#00ffff",
-  "#5f0000",
-  "#5f005f",
-  "#5f0087",
-  "#5f00af",
-  "#5f00d7",
-  "#5f00ff",
-  "#5f5f00",
-  "#5f5f5f",
-  "#5f5f87",
-  "#5f5faf",
-  "#5f5fd7",
-  "#5f5fff",
-  "#5f8700",
-  "#5f875f",
-  "#5f8787",
-  "#5f87af",
-  "#5f87d7",
-  "#5f87ff",
-  "#5faf00",
-  "#5faf5f",
-  "#5faf87",
-  "#5fafaf",
-  "#5fafd7",
-  "#5fafff",
-  "#5fd700",
-  "#5fd75f",
-  "#5fd787",
-  "#5fd7af",
-  "#5fd7d7",
-  "#5fd7ff",
-  "#5fff00",
-  "#5fff5f",
-  "#5fff87",
-  "#5fffaf",
-  "#5fffd7",
-  "#5fffff",
-  "#870000",
-  "#87005f",
-  "#870087",
-  "#8700af",
-  "#8700d7",
-  "#8700ff",
-  "#875f00",
-  "#875f5f",
-  "#875f87",
-  "#875faf",
-  "#875fd7",
-  "#875fff",
-  "#878700",
-  "#87875f",
-  "#878787",
-  "#8787af",
-  "#8787d7",
-  "#8787ff",
-  "#87af00",
-  "#87af5f",
-  "#87af87",
-  "#87afaf",
-  "#87afd7",
-  "#87afff",
-  "#87d700",
-  "#87d75f",
-  "#87d787",
-  "#87d7af",
-  "#87d7d7",
-  "#87d7ff",
-  "#87ff00",
-  "#87ff5f",
-  "#87ff87",
-  "#87ffaf",
-  "#87ffd7",
-  "#87ffff",
-  "#af0000",
-  "#af005f",
-  "#af0087",
-  "#af00af",
-  "#af00d7",
-  "#af00ff",
-  "#af5f00",
-  "#af5f5f",
-  "#af5f87",
-  "#af5faf",
-  "#af5fd7",
-  "#af5fff",
-  "#af8700",
-  "#af875f",
-  "#af8787",
-  "#af87af",
-  "#af87d7",
-  "#af87ff",
-  "#afaf00",
-  "#afaf5f",
-  "#afaf87",
-  "#afafaf",
-  "#afafd7",
-  "#afafff",
-  "#afd700",
-  "#afd75f",
-  "#afd787",
-  "#afd7af",
-  "#afd7d7",
-  "#afd7ff",
-  "#afff00",
-  "#afff5f",
-  "#afff87",
-  "#afffaf",
-  "#afffd7",
-  "#afffff",
-  "#d70000",
-  "#d7005f",
-  "#d70087",
-  "#d700af",
-  "#d700d7",
-  "#d700ff",
-  "#d75f00",
-  "#d75f5f",
-  "#d75f87",
-  "#d75faf",
-  "#d75fd7",
-  "#d75fff",
-  "#d78700",
-  "#d7875f",
-  "#d78787",
-  "#d787af",
-  "#d787d7",
-  "#d787ff",
-  "#d7af00",
-  "#d7af5f",
-  "#d7af87",
-  "#d7afaf",
-  "#d7afd7",
-  "#d7afff",
-  "#d7d700",
-  "#d7d75f",
-  "#d7d787",
-  "#d7d7af",
-  "#d7d7d7",
-  "#d7d7ff",
-  "#d7ff00",
-  "#d7ff5f",
-  "#d7ff87",
-  "#d7ffaf",
-  "#d7ffd7",
-  "#d7ffff",
-  "#ff0000",
-  "#ff005f",
-  "#ff0087",
-  "#ff00af",
-  "#ff00d7",
-  "#ff00ff",
-  "#ff5f00",
-  "#ff5f5f",
-  "#ff5f87",
-  "#ff5faf",
-  "#ff5fd7",
-  "#ff5fff",
-  "#ff8700",
-  "#ff875f",
-  "#ff8787",
-  "#ff87af",
-  "#ff87d7",
-  "#ff87ff",
-  "#ffaf00",
-  "#ffaf5f",
-  "#ffaf87",
-  "#ffafaf",
-  "#ffafd7",
-  "#ffafff",
-  "#ffd700",
-  "#ffd75f",
-  "#ffd787",
-  "#ffd7af",
-  "#ffd7d7",
-  "#ffd7ff",
-  "#ffff00",
-  "#ffff5f",
-  "#ffff87",
-  "#ffffaf",
-  "#ffffd7",
-  "#ffffff",
-  "#080808",
-  "#121212",
-  "#1c1c1c",
-  "#262626",
-  "#303030",
-  "#3a3a3a",
-  "#444444",
-  "#4e4e4e",
-  "#585858",
-  "#626262",
-  "#6c6c6c",
-  "#767676",
-  "#808080",
-  "#8a8a8a",
-  "#949494",
-  "#9e9e9e",
-  "#a8a8a8",
-  "#b2b2b2",
-  "#bcbcbc",
-  "#c6c6c6",
-  "#d0d0d0",
-  "#dadada",
-  "#e4e4e4",
-  "#eeeeee"
-]