Search for a string in Enum and return the Enum

check out System.Enum.Parse:

enum Colors {Red, Green, Blue}

// your code:
Colors color = (Colors)System.Enum.Parse(typeof(Colors), "Green");

You can cast the int to an enum

(MyColour)2

There is also the option of Enum.Parse

(MyColour)Enum.Parse(typeof(MyColour), "Red")

Given the latest and greatest changes to .NET (+ Core) and C# 7, here is the best solution:

var ignoreCase = true;
Enum.TryParse("red", ignoreCase , out MyColours colour);

colour variable can be used within the scope of Enum.TryParse

All you need is Enum.Parse.

I marked OregonGhost's answer +1, then I tried to use the iteration and realised it wasn't quite right because Enum.GetNames returns strings. You want Enum.GetValues:

public MyColours GetColours(string colour)
{  
   foreach (MyColours mc in Enum.GetValues(typeof(MyColours))) 
   if (mc.ToString() == surveySystem) 
      return mc;

   return MyColors.Default;
}