diff --git a/PyIGL_viewer/shaders/per_vertex_color.frag b/PyIGL_viewer/shaders/per_vertex_color.frag
index be607b3..aaf952a 100644
--- a/PyIGL_viewer/shaders/per_vertex_color.frag
+++ b/PyIGL_viewer/shaders/per_vertex_color.frag
@@ -1,8 +1,8 @@
 #version 330
 
-in vec4 color;
+in vec3 color;
 
-out vec4 outputColor;
+out vec3 outputColor;
 void main()
 {
     outputColor = color;