Add Visuals::error_fg_color and Visuals::warn_fg_color

egui/src/lib.rs

@@ -375,7 +375,7 @@ pub fn warn_if_debug_build(ui: &mut crate::Ui) {
         ui.label(
             RichText::new("‼ Debug build ‼")
                 .small()
-                .color(crate::Color32::RED),
+                .color(ui.visuals().warn_fg_color),
         )
         .on_hover_text("egui was compiled with debug assertions enabled.");
     }

egui/src/painter.rs

@@ -219,7 +219,8 @@ impl Painter {
     }
 
     pub fn error(&self, pos: Pos2, text: impl std::fmt::Display) -> Rect {
-        self.debug_text(pos, Align2::LEFT_TOP, Color32::RED, format!("🔥 {}", text))
+        let color = self.ctx.style().visuals.error_fg_color;
+        self.debug_text(pos, Align2::LEFT_TOP, color, format!("🔥 {}", text))
     }
 
     /// text with a background

egui/src/style.rs

@@ -446,6 +446,12 @@ pub struct Visuals {
     /// Background color behind code-styled monospaced labels.
     pub code_bg_color: Color32,
 
+    /// A good color for warning text (e.g. orange).
+    pub warn_fg_color: Color32,
+
+    /// A good color for error text (e.g. red).
+    pub error_fg_color: Color32,
+
     pub window_rounding: Rounding,
     pub window_shadow: Shadow,
 
@@ -669,6 +675,8 @@ impl Visuals {
             faint_bg_color: Color32::from_gray(35),
             extreme_bg_color: Color32::from_gray(10), // e.g. TextEdit background
             code_bg_color: Color32::from_gray(64),
+            warn_fg_color: Color32::from_rgb(255, 143, 0), // orange
+            error_fg_color: Color32::from_rgb(255, 0, 0),  // red
             window_rounding: Rounding::same(6.0),
             window_shadow: Shadow::big_dark(),
             popup_shadow: Shadow::small_dark(),
@@ -691,6 +699,8 @@ impl Visuals {
             faint_bg_color: Color32::from_gray(242),
             extreme_bg_color: Color32::from_gray(255), // e.g. TextEdit background
             code_bg_color: Color32::from_gray(230),
+            warn_fg_color: Color32::from_rgb(255, 0, 0), // red also, beecause orange doesn't look great because of https://github.com/emilk/egui/issues/1455
+            error_fg_color: Color32::from_rgb(255, 0, 0), // red
             window_shadow: Shadow::big_light(),
             popup_shadow: Shadow::small_light(),
             ..Self::dark()
@@ -1140,6 +1150,8 @@ impl Visuals {
             faint_bg_color,
             extreme_bg_color,
             code_bg_color,
+            warn_fg_color,
+            error_fg_color,
             window_rounding,
             window_shadow,
             popup_shadow,
@@ -1175,11 +1187,16 @@ impl Visuals {
         ui.collapsing("Widgets", |ui| widgets.ui(ui));
         ui.collapsing("Selection", |ui| selection.ui(ui));
 
-        ui_color(
+        ui.horizontal(|ui| {
-            ui,
+            ui_color(
-            &mut widgets.noninteractive.fg_stroke.color,
+                ui,
-            "Text color",
+                &mut widgets.noninteractive.fg_stroke.color,
-        );
+                "Text color",
+            );
+            ui_color(ui, warn_fg_color, RichText::new("Warnings"));
+            ui_color(ui, error_fg_color, RichText::new("Errors"));
+        });
+
         ui_color(ui, code_bg_color, RichText::new("Code background").code()).on_hover_ui(|ui| {
             ui.horizontal(|ui| {
                 ui.spacing_mut().item_spacing.x = 0.0;

egui_demo_app/src/apps/http_app.rs

@@ -95,7 +95,7 @@ impl eframe::App for HttpApp {
                         Err(error) => {
                             // This should only happen if the fetch API isn't available or something similar.
                             ui.colored_label(
-                                egui::Color32::RED,
+                                ui.visuals().error_fg_color,
                                 if error.is_empty() { "Error" } else { error },
                             );
                         }

egui_demo_lib/src/demo/misc_demo_window.rs

@@ -443,7 +443,7 @@ impl Tree {
     fn children_ui(&mut self, ui: &mut Ui, depth: usize) -> Action {
         if depth > 0
             && ui
-                .button(RichText::new("delete").color(Color32::RED))
+                .button(RichText::new("delete").color(ui.visuals().warn_fg_color))
                 .clicked()
         {
             return Action::Delete;

examples/download_image/src/main.rs

@@ -41,7 +41,7 @@ impl eframe::App for MyApp {
                 ui.spinner(); // still loading
             }
             Some(Err(err)) => {
-                ui.colored_label(egui::Color32::RED, err); // something went wrong
+                ui.colored_label(ui.visuals().error_fg_color, err); // something went wrong
             }
             Some(Ok(image)) => {
                 image.show_max_size(ui, ui.available_size());