diff --git a/render-wasm/src/render.rs b/render-wasm/src/render.rs
index f4d4401fbd..976f3695db 100644
--- a/render-wasm/src/render.rs
+++ b/render-wasm/src/render.rs
@@ -414,6 +414,10 @@ impl RenderState {
         })
     }
 
+    pub fn options(&self) -> RenderOptions {
+        self.options
+    }
+
     /// Combines every visible layer blur currently active (ancestors + shape)
     /// into a single equivalent blur. Layer blur radii compound by adding their
     /// variances (σ² = radius²), so we:
@@ -1446,7 +1450,8 @@ impl RenderState {
                 debug::render(self);
             }
 
-            ui::render(self, shapes);
+            // FIXME: get actual theme from options
+            ui::render(self, shapes, &ui::DarkTheme::default());
             debug::render_wasm_label(self);
 
             self.flush_and_submit();
@@ -2669,7 +2674,8 @@ impl RenderState {
             debug::render(self);
         }
 
-        ui::render(self, tree);
+        // FIXME: get actual theme from options
+        ui::render(self, tree, &ui::DarkTheme::default());
         debug::render_wasm_label(self);
 
         Ok(())
diff --git a/render-wasm/src/render/ui.rs b/render-wasm/src/render/ui.rs
index bb7cc72c0f..dd2530e6d5 100644
--- a/render-wasm/src/render/ui.rs
+++ b/render-wasm/src/render/ui.rs
@@ -4,7 +4,14 @@ use super::{RenderState, ShapesPoolRef, SurfaceId};
 use crate::render::grid_layout;
 use crate::shapes::{Layout, Type};
 
-pub fn render(render_state: &mut RenderState, shapes: ShapesPoolRef) {
+mod themes;
+use themes::UITheme;
+
+#[allow(unused_imports)]
+pub use themes::{DarkTheme, LightTheme};
+
+pub fn render(render_state: &mut RenderState, shapes: ShapesPoolRef, theme: &impl UITheme) {
+    let render_options = render_state.options();
     let canvas = render_state.surfaces.canvas(SurfaceId::UI);
 
     canvas.clear(Color4f::new(0.0, 0.0, 0.0, 0.0));
@@ -67,9 +74,18 @@ pub fn render(render_state: &mut RenderState, shapes: ShapesPoolRef) {
     }
 
     canvas.restore();
+
+    if render_options.are_rulers_enabled() {
+        render_rulers(canvas, theme);
+    }
+
     render_state.surfaces.draw_into(
         SurfaceId::UI,
         SurfaceId::Target,
         Some(&skia::Paint::default()),
     );
 }
+
+fn render_rulers(canvas: &skia::Canvas, _theme: &impl UITheme) {
+    canvas.draw_rect(skia::Rect::new(0.0, 0.0, 100.0, 100.0), &skia::Paint::default());
+}
\ No newline at end of file
diff --git a/render-wasm/src/render/ui/themes.rs b/render-wasm/src/render/ui/themes.rs
new file mode 100644
index 0000000000..087c8bd144
--- /dev/null
+++ b/render-wasm/src/render/ui/themes.rs
@@ -0,0 +1,31 @@
+use crate::shapes::Color;
+
+pub trait UITheme {
+    fn panel_background_color(&self) -> Color;
+    fn panel_border_color(&self) -> Color;
+}
+
+#[derive(Default, Clone, Copy, PartialEq)]
+pub struct LightTheme {}
+
+impl UITheme for LightTheme {
+    fn panel_background_color(&self) -> Color {
+        Color::new(0xffffffff)
+    }
+    fn panel_border_color(&self) -> Color {
+        Color::new(0xffeef0f2)
+    }
+}
+
+#[derive(Default, Clone, Copy, PartialEq)]
+pub struct DarkTheme {}
+
+impl UITheme for DarkTheme {
+    fn panel_background_color(&self) -> Color {
+        Color::new(0xff18181a)
+    }
+
+    fn panel_border_color(&self) -> Color {
+        Color::new(0xff2e3434)
+    }
+}
\ No newline at end of file