diff --git a/src/pipelines/render/render.wgsl b/src/pipelines/render/render.wgsl
index 8cde5bf..aef8c28 100644
--- a/src/pipelines/render/render.wgsl
+++ b/src/pipelines/render/render.wgsl
@@ -20,11 +20,11 @@ fn fragment(@location(0) uv: vec2<f32>) -> @location(0) vec4<f32> {
   let speciesBStrength = clamp(pow(traces.g, settings.clarity), 0, 1);
   let brushStrength = traces.a;
 
+  let agentColor =  settings.speciesColorA * speciesAStrength + settings.speciesColorB * speciesBStrength;
+  let agentStrength = speciesAStrength + speciesBStrength;
 
   let rgbColor = sqrt(
-    settings.speciesColorA * speciesAStrength + 
-    settings.speciesColorB * speciesBStrength +
-    settings.brushColor * brushStrength
+    mix(agentColor, settings.brushColor * brushStrength, clamp(brushStrength - agentStrength, 0, 1))
   );
   return vec4(backgroundColor - rgbColor, 1);
 }
diff --git a/src/settings.ts b/src/settings.ts
index c14b5ba..17eb480 100644
--- a/src/settings.ts
+++ b/src/settings.ts
@@ -36,7 +36,7 @@ export const settings: GameLoopSettings &
   diffusionRateTrails: 0.4, // inverse
   decayRateTrails: 0.9, // inverse
   diffusionRateBrush: 4, // inverse
-  decayRateBrush: 0.99, // inverse
+  decayRateBrush: 0.995, // inverse
 
   brushColor: palette.blue,
   speciesColorA: palette.yellow,