diff --git a/src/org/oscim/renderer/Shaders.java b/src/org/oscim/renderer/Shaders.java
index 4a176719..b9471701 100644
--- a/src/org/oscim/renderer/Shaders.java
+++ b/src/org/oscim/renderer/Shaders.java
@@ -107,7 +107,9 @@ public final class Shaders {
 			+ "uniform vec4 u_color;"
 			+ "varying float z;"
 			+ "void main() {"
-			+ "if (z < 0.0)"
+			+ "if (z < -1.0)"
+			+ "  gl_FragColor = vec4(0.0, z + 2.0, 0.0, 1.0)*0.8;"
+			+ "else if (z < 0.0)"
 			+ "  gl_FragColor = vec4(z * -1.0, 0.0, 0.0, 1.0)*0.8;"
 			+ "else if (z < 1.0)"
 			+ "  gl_FragColor = vec4(0.0, 0.0, z, 1.0)*0.8;"