ScriptUI: fix script-drawn colours showing too bright

paint_draw passed a script's 0 to 1 colour values to egui::Rgba, which
stores linear light. egui then applied the sRGB curve, so every
fillPath, strokePath and drawString colour drew too bright. For example,
#2B2B2B drew as RGB 114 and #F28C28 as 249, 196, 110.

After Effects treats these values as plain screen colours. Convert them
with the existing to_color32 helper instead.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/ui-egui/src/panels/gradient_editor.rs

@@ -241,7 +241,7 @@ fn commit(app: &mut EffectcraftApp, ctx: &egui::Context) {
     }
 }
 
-fn to_color32(c: [f32; 4]) -> Color32 {
+pub(super) fn to_color32(c: [f32; 4]) -> Color32 {
     let b = |v: f32| (v.clamp(0.0, 1.0) * 255.0).round() as u8;
     Color32::from_rgba_unmultiplied(b(c[0]), b(c[1]), b(c[2]), b(c[3]))
 }

crates/ui-egui/src/panels/scriptui_view.rs

@@ -256,20 +256,22 @@ fn draw_widget(app: &mut EffectcraftApp, ui: &mut egui::Ui, origin: egui::Pos2,
     }
 }
 
+/// A draw-list colour (`None` is the theme colour). Script colours are display (sRGB) values
+/// in 0..1, as in After Effects, not linear light: `[43/255, 43/255, 43/255, 1]` is RGB 43.
+fn draw_color(c: &Option<[f32; 4]>, theme: Color32) -> Color32 {
+    c.map_or(theme, super::gradient_editor::to_color32)
+}
+
 /// Paint an onDraw draw list in `rect` (control coordinates → screen).
 fn paint_draw(ui: &egui::Ui, rect: Rect, ops: &[DrawOp], t: &Tokens, services: &dyn Services) {
     let p = ui.painter().with_clip_rect(rect.intersect(ui.clip_rect()));
-    let col = |c: &Option<[f32; 4]>, theme: Color32| match c {
-        Some(c) => egui::Rgba::from_rgba_unmultiplied(c[0], c[1], c[2], c[3]).into(),
-        None => theme,
-    };
     let at = |x: f64, y: f64| rect.min + vec2(x as f32, y as f32);
     for op in ops {
         match op {
             DrawOp::Fill { color, path } => {
                 // Any path shape (concave, self-intersecting, with holes): non-zero winding
                 // triangles, not egui's convex-only polygon fill.
-                let c = col(color, t.field_bg);
+                let c = draw_color(color, t.field_bg);
                 let mut mesh = egui::Mesh::default();
                 for tri in PathSeg::fill_triangles(path, 48, false) {
                     let base = mesh.vertices.len() as u32;
@@ -283,14 +285,14 @@ fn paint_draw(ui: &egui::Ui, rect: Rect, ops: &[DrawOp], t: &Tokens, services: &
                 }
             }
             DrawOp::Stroke { color, width, path } => {
-                let s = Stroke::new(*width as f32, col(color, t.text));
+                let s = Stroke::new(*width as f32, draw_color(color, t.text));
                 for (pts, closed) in PathSeg::polylines(path, 48) {
                     let pts: Vec<egui::Pos2> = pts.iter().map(|q| at(q[0], q[1])).collect();
                     p.add(if closed { egui::Shape::closed_line(pts, s) } else { egui::Shape::line(pts, s) });
                 }
             }
             DrawOp::Text { text, color, x, y, size, .. } => {
-                p.text(at(*x, *y), Align2::LEFT_TOP, text, Tokens::ui(*size as f32), col(color, t.text));
+                p.text(at(*x, *y), Align2::LEFT_TOP, text, Tokens::ui(*size as f32), draw_color(color, t.text));
             }
             DrawOp::Image { image, x, y, w, h } => {
                 let tex = image.as_ref().and_then(|i| image_texture(ui.ctx(), i, services));
@@ -592,3 +594,18 @@ pub fn sync_panels(app: &mut EffectcraftApp) {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// Script colours are sRGB, not linear: `#2B2B2B` drew as RGB 114 when read as linear light.
+    #[test]
+    fn draw_colours_are_srgb() {
+        let v = 43.0 / 255.0;
+        assert_eq!(draw_color(&Some([v, v, v, 1.0]), Color32::RED), Color32::from_rgb(43, 43, 43));
+        let orange = [242.0 / 255.0, 140.0 / 255.0, 40.0 / 255.0, 1.0];
+        assert_eq!(draw_color(&Some(orange), Color32::RED), Color32::from_rgb(242, 140, 40));
+        assert_eq!(draw_color(&None, Color32::RED), Color32::RED, "no colour is the theme colour");
+    }
+}