There are five rooms: purple (where you start), red, yellow, green and blue. Draw a large pentagon and join every corner to every other (so that you have a pentagram inside a pentagon). Now label each of the corners so each has a different one of these colours (the order doesn't matter). Take any two objects and pass through one of the doors in the purple room that you can get through. Note what object you used to get through the door and which room you end up in. Write the name of the object on the line joining the purple corner of your pentagon to the corner for the colour of the room you end up in. For example, if you use the feather and end up in the green room, then write "feather" on line joining the purple and green corners of the pentagon. Now go through the door you just came through to get back the purple room, and repeat for another door. (Be careful not to go through the middle door, which will take you back outside.)
Keep going until you have done as much as you can, then return to the purple room, speak to the faery and pick a different combination. Keep doing the above until you have written on each of the ten lines on your diagram.
Pick one of the objects. Lightly sketch out a new pentagram in a pentagon and copy on to it the exact arrangment of lines that are labelled with the object you have chosen. Repeat (on a new pentagon plus pentagram each time) with the other five objects. This gives you six new diagrams.
Now take these diagrams two at a time in all possible combinations (there are 15 ways to do this). If you find a pair of diagrams that enable you to trace a path starting in the purple room and visiting all of the other rooms, then the two objects in this pair are the two you need to choose to solve the puzzle.