I am soooo confused...
So If the mouth is closed I must spot that color of the trapped fly. Once I spot it elsewhere my plant opens and changes color and I can attract that or lower flies.

.... does the rainbow fly plant work different? I have a rainbow trap with 4 trapped flies. I spotted a rainbow fly in another garden but it did not open the mouth in my garden... why oh why?? please help so how did i get 1 rainbow fly awaiting then?

The rainbow mouths don't open.  Once they are all closed, the trap is complete.

but people have the rainbow plant in their garden attracting loads of flies with nothing in the "currently awaiting"...
and why / how do i have 1 awaiting rainbow fly?

thanks, as always cobweb

The completed rainbow plant attracts all colours of fly.  It isn't "currently awaiting" anything though, as the trap is complete, so doesn't need anything else to complete it.  All the rainbow flies are (and remain) trapped once you've finished it.
 
You are waiting for one rainbow fly because that's all you need to complete your trap.  Once that fly is spotted and trapped, all the mouths are (and remain) closed.

ahhhhhh i just saw i had 5 rainbow flies which i finished years back but i must still trap the 5th one, thanks Tracey, for helping 'pinky'. got it!!
'

i just got a violet fly even tough 4 rainbow mouths are closed and 1 open. I wasnt sure i could attract anything with my cactus as is... but it appears i can so that is cool thank you.

Each mouth attracts its own colour, and the one below.  So your open rainbow mouth will attract violet flies as well as one rainbow.

I am not sure how these flies are attracted do they only come if you have a plant with open mouth and the colour of the mouth

When you have a plant with an open mouth, you are attracting that colour of fly.  When the fly is spotted, it becomes trapped in the mouth, and you release it by spotting that colour of fly in another garden.  When it's released, the mouth opens to the next colour, and you're attracting that colour of fly.

You can see what you need to do if you hover your mouse over the fly trap.  Anything which says is "currently trapped" needs you to spot that colour in another garden to release it.  Anything which says "currently attracting" is what you can currently attract.

So at the moment you have four red flies trapped, and one open red mouth.  You will attract the red fly once, which will close the mouth.  You need to spot red flies in other gardens, which will release the ones trapped in your garden.  Once you release them, the mouth will turn to orange and you'll be attracting orange flies.