If you have the Gameboy Color version of Link's Awakening then you should know that there is some new stuff in it. This is were we discuss it all! Remember you can use the walkthrough for the original version of the game and just use this walkthrough for the New Dungeon and to find the Photo Locations.
Indeed there is a secret Color dungeon in Link's Awakening DX.
To find the secret dungeon you will need to goto the Graveyard. There should be a part where you can see five gravestones on the screen. If you push them in a correct sequence the entrance will open. To find what the sequence is, you will need to knock the book of the shelf in the Library (using shoes to ram the shelf).
If you are using a regular Gameboy, you will not be able to play this dungeon becuase it's all Color related. The skeleton guards will turn you away if you try to use an old Gameboy.
You can find two tunics in this level, a red and blue tunic. The red tunic increases attacking power and the blue tunic decreases damage you take.
Another new feature of Zelda DX is that you can find photo's in the game and print them out using your Pocket Printer. There are 12 different locations in all. The locations of all the Photo's are in this picture below.