Added text buttons and button groups.

src/utils/color.lua

@@ -0,0 +1,30 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local make_class = require 'src.utils.classes'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+local Color = make_class()
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function Color:_init(r, g, b)
+    self.r = r ~= nil and r or 255
+    self.g = g ~= nil and g or 255
+    self.b = b ~= nil and b or 255
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return Color