diff --git a/src/colour.c b/src/colour.c
index 0cce656..625f459 100644
--- a/src/colour.c
+++ b/src/colour.c
@@ -13,6 +13,7 @@ glColour cGrey20    = { .r = 0.20, .g = 0.20, .b = 0.20, .a = 1. };
 glColour cGrey10    = { .r = 0.10, .g = 0.10, .b = 0.10, .a = 1. };
 glColour cBlack     = { .r = 0.00, .g = 0.00, .b = 0.00, .a = 1. };
 
+glColour cTrans			= { .r = 1.00, .g = 1.00, .b = 1.00, .a = 0. };
 glColour cGreen     = { .r = 0.20, .g = 0.80, .b = 0.20, .a = 1. };
 glColour cDarkRed   = { .r = 0.60, .g = 0.10, .b = 0.10, .a = 1. };
 glColour cRed       = { .r = 0.80, .g = 0.20, .b = 0.20, .a = 1. };
diff --git a/src/colour.h b/src/colour.h
index a2b1e10..18e29a0 100644
--- a/src/colour.h
+++ b/src/colour.h
@@ -22,6 +22,7 @@ extern glColour cGrey30;
 extern glColour cGrey20;
 extern glColour cGrey10;
 
+extern glColour cTrans;
 extern glColour cGreen;
 extern glColour cDarkRed;
 extern glColour cRed;