Keep selected fuzzy completions readable on white foregrounds

src/prompt_toolkit/styles/defaults.py

@@ -74,7 +74,7 @@
     ("completion-menu.completion fuzzymatch.outside", "fg:#444444"),
     ("completion-menu.completion fuzzymatch.inside", "bold"),
     ("completion-menu.completion fuzzymatch.inside.character", "underline"),
-    ("completion-menu.completion.current fuzzymatch.outside", "fg:default"),
+    ("completion-menu.completion.current fuzzymatch.outside", "fg:#444444"),
     ("completion-menu.completion.current fuzzymatch.inside", "nobold"),
     # Styling of readline-like completions.
     ("readline-like-completions", ""),

tests/test_default_style.py

@@ -0,0 +1,13 @@
+from prompt_toolkit.styles.defaults import default_ui_style
+
+
+def test_selected_fuzzy_completion_outside_colors() -> None:
+    attrs = default_ui_style().get_attrs_for_style_str(
+        "class:completion-menu.completion.current class:fuzzymatch.outside"
+    )
+
+    # Reverse makes the foreground the background: it must not depend on the
+    # terminal foreground, which can be white like the selected text.
+    assert attrs.color == "444444"
+    assert attrs.bgcolor == "ffffff"
+    assert attrs.reverse