fix hsl-rgb convert CS flag

colours.c

@@ -89,6 +89,7 @@ struct colour get_hs_l_v(struct colour c, enum colour_space sp) {
             ret.s = (ret.v - ret.l) / m_min(arr, 2); 
         }
     }
+    ret.sp = CS_HSL;
     return ret;
 }
 

colours.h

@@ -8,9 +8,10 @@
 #define H_COLOURS
 
 enum colour_space {
-    CS_RGB = 0, // default to RGB
-    CS_HSV = 1,
-    CS_HSL = 2,
+    CS_INVALID = 0,
+    CS_RGB = 1, // default to RGB
+    CS_HSV = 2,
+    CS_HSL = 3,
 };
 
 struct colour {