diff --git a/src/graphics_api_impl.rs b/src/graphics_api_impl.rs
index 8ce7196..c72b380 100644
--- a/src/graphics_api_impl.rs
+++ b/src/graphics_api_impl.rs
@@ -133,10 +133,11 @@ impl AglApi for GraphicsRenderer {
     }
 }
 
-/// Interpolate between two colors according to a factor.
+/// Linearly interpolate between two colors according to a factor.
+/// This method is cheap, perfectly accurate for shades of gray, and
+/// reasonably accurate for other colors; if better results are
+/// needed, LCH interpolation should be used instead.
 fn lerp_rgba(a: RGBA, b: RGBA, fac: f32) -> RGBA {
-    // TODO: This is probably the wrong way to mix colors, but it's
-    // simple and works for now.
     RGBA {
         r: ((b.r as f32 - a.r as f32) * fac + a.r as f32) as _,
         g: ((b.g as f32 - a.g as f32) * fac + a.g as f32) as _,