cli: use the terminal palette for low-confidence groups

rust/cli/CHANGELOG.md

@@ -11,6 +11,7 @@
 
 ### Patch
 
+- Use the terminal palette for low-confidence groups so they stay readable on light backgrounds (fixes #1243)
 - Fix panic with JSON output when a file name is not UTF-8
 - Remove deprecated `package.authors` field in `Cargo.toml`
 - Update dependencies

rust/cli/src/main.rs

@@ -910,8 +910,8 @@ impl Response {
 
     fn color(&self, result: ColoredString) -> ColoredString {
         use colored::Colorize as _;
-        // We only use true colors (except for errors). If the terminal doesn't support true colors,
-        // the colored crate will automatically choose the closest one.
+        // We only use true colors for the highlighted groups (and red for errors). If the terminal
+        // doesn't support true colors, the colored crate will automatically choose the closest one.
         match &self.result {
             Err(_) => result.bold().red(),
             Ok(x) => match x.info().group {
@@ -924,7 +924,11 @@ impl Response {
                 "executable" => result.truecolor(0xec, 0x48, 0x99),  // Pink 500
                 "image" => result.truecolor(0x06, 0xb6, 0xd4),       // Cyan 500
                 "video" => result.truecolor(0x10, 0xb9, 0x81),       // Emerald 500
-                _ => result.bold().truecolor(0xcc, 0xcc, 0xcc),
+                // Use the terminal palette for the remaining groups (e.g. "text" and "unknown",
+                // used for low-confidence reports) instead of a fixed light gray. The palette
+                // adapts to the user's terminal theme: bright black renders as a dark gray on
+                // light backgrounds and as a light gray on dark backgrounds (fixes #1243).
+                _ => result.bold().bright_black(),
             },
         }
     }

rust/cli/test.sh

@@ -53,6 +53,21 @@ info "Test symlinks"
 [ "$(magika --format=%l LICENSE)" = txt ] || error "does not follow symlinks"
 [ "$(magika --format=%l --no-dereference LICENSE)" = symlink ] || error "follows symlinks"
 
+info "Test low-confidence groups are readable on light backgrounds"
+( dir=$(mktemp -d)
+  trap "rm -rf $dir" EXIT
+  file=$dir/text.txt
+  printf 'hello, world\n' > $file
+  output=$(magika --colors $file)
+  # The "text" group falls back to the terminal palette (bright black) instead of the fixed
+  # light gray #cccccc that is invisible on light-background terminals (fixes #1243).
+  printf '%s' "$output" | grep -qF $'\033[1;90m' \
+    || error "low-confidence groups do not use the terminal palette"
+  if printf '%s' "$output" | grep -qF $'\033[1;38;2;204;204;204m'; then
+    error "low-confidence groups still use the light gray #cccccc"
+  fi
+)
+
 test_error() {
   files="$1"
   expected="$2"