diff --git a/builtin/common/misc_helpers.lua b/builtin/common/misc_helpers.lua
index f9b572d..776be29 100644
--- a/builtin/common/misc_helpers.lua
+++ b/builtin/common/misc_helpers.lua
@@ -511,6 +511,12 @@ function core.explode_scrollbar_event(evt)
 	return retval
 end
 
+--------------------------------------------------------------------------------
+function core.rgba(r, g, b, a)
+	return a and string.format("#%02X%02X%02X%02X", r, g, b, a) or
+			string.format("#%02X%02X%02X", r, g, b)
+end
+
 --------------------------------------------------------------------------------
 function core.pos_to_string(pos, decimal_places)
 	local x = pos.x