Orange was only used for feng shui in the game cube version.
Its just yellow, red & green in this game as in acww & accf.
I don't know for sure if it is just the main room - I thought it was all rooms but not seen any research info as yet about it.
About the entrance - its difficult to get a good count for green - the bath mat (x2 green) was walkable over in accf - and hopefully is in NL - so look for that and it may be placeable over the entrance.
Liquefy's faq on gamefaqs is the most accurate for feng shui help.