diff --git a/builtin/common/misc_helpers.lua b/builtin/common/misc_helpers.lua
index f9b572d9f..776be29d8 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
diff --git a/doc/client_lua_api.md b/doc/client_lua_api.md
index 43b33ac97..3bd1e3567 100644
--- a/doc/client_lua_api.md
+++ b/doc/client_lua_api.md
@@ -794,6 +794,10 @@ Call these functions only at load time!
     * See documentation on `minetest.compress()` for supported compression methods.
     * currently supported.
     * `...` indicates method-specific arguments. Currently, no methods use this.
+* `minetest.rgba(red, green, blue[, alpha])`: returns a string
+    * Each argument is a 8 Bit unsigned integer
+    * Returns the ColorString from rgb or rgba values
+    * Example: `minetest.rgba(10, 20, 30, 40)`, returns `"#0A141E28"`
 * `minetest.encode_base64(string)`: returns string encoded in base64
     * Encodes a string in base64.
 * `minetest.decode_base64(string)`: returns string
diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 9bd92b34a..664ad960a 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -580,7 +580,7 @@ Example (colored grass block):
         description = "Dirt with Grass",
         -- Regular tiles, as usual
         -- The dirt tile disables palette coloring
-        tiles = {{name = "default_grass.png"}, 
+        tiles = {{name = "default_grass.png"},
             {name = "default_dirt.png", color = "white"}},
         -- Overlay tiles: define them in the same style
         -- The top and bottom tile does not have overlay
@@ -2958,6 +2958,10 @@ These functions return the leftover itemstack.
     * See documentation on `minetest.compress()` for supported compression methods.
     * currently supported.
     * `...` indicates method-specific arguments. Currently, no methods use this.
+* `minetest.rgba(red, green, blue[, alpha])`: returns a string
+    * Each argument is a 8 Bit unsigned integer
+    * Returns the ColorString from rgb or rgba values
+    * Example: `minetest.rgba(10, 20, 30, 40)`, returns `"#0A141E28"`
 * `minetest.encode_base64(string)`: returns string encoded in base64
     * Encodes a string in base64.
 * `minetest.decode_base64(string)`: returns string