improve results screen

shader/grayscale_alpha.fs

@@ -0,0 +1,13 @@
+// fragment shader
+#version 330
+in vec2 fragTexCoord;
+uniform sampler2D texture0;
+out vec4 finalColor;
+uniform float ext_alpha;
+void main() {
+    vec4 texColor = texture(texture0, fragTexCoord);
+    vec3 last_color = vec3(1.0, 253.0/255.0, (186.0*0.80)/255.0);
+    // Use luminance as alpha (0.0 = transparent, 1.0 = opaque)
+    float alpha = ((texColor.r + texColor.g + texColor.b)/3)*0.70;
+    finalColor = vec4(last_color, alpha * ext_alpha);
+}