The two myAction functions below seem to be equivalent and, for this small case, show an interesting economy of code, but being far from a Haskell expert, I have to ask, is the first function as small (code wise) as it could be?

Michael

import Control.Applicative

data Color
    = Red
    | Blue
    | Green
    | Yellow
    | Orange
    | Brown
    | Black
    | White
    deriving (Show, Read, Eq, Enum, Ord, Bounded)

-- myAction :: IO Color
-- myAction = getLine
--           >>= \str -> return (read str :: Color)

First, you don't need the type annotation here. Haskell will infer it from the annotation on myAction. (You also don't need the type on myAction, but that's not important now.)

myAction = getLine >>= \str -> return (read str)

Second, you have the pattern \x -> f (g x), so you can replace the lambda with function composition.

myAction = getLine >>= return . read

Third, there is a standard function liftM, defined in Control.Monad, where liftM f m = m >>= return . f, so

myAction = liftM read getLine

Finally, we expect an instance of Monad to also be an instance of Functor, with fmap = liftM, and we also have f <$> m = fmap f m, so

myAction :: IO Color
myAction = read <$> getLine