What you'll get:

A .zip file with 5.blend files, one for each species

How to append the files in your scene:

1. Go to file>append
2. Browse to the .blend file of the flower species you want to place
3. Inside this folder, go to >object
4. Select all the objects in this folder and press append

How to change the color variations:

1. Select the flower you want to change
2. Open the node editor and select the slot you want to change. Most of my models have leaves, flower and stem slots. Most of the color variations happen in the flower slots.
3. Locate the green field inside the node tree, here you will find the controls for the shader. In the case of the Hellebore model, there is an additional green field where you can connect one of the color variations presets. Their names indicate what colors you will get.