These flowers are looking great @yukinoh1989 ! I believe I found the right file in the drive to look at (WIP_nature_FG-flowers_yukinoh1989_01), but I did not see the textures in the textures folder, so I couldn’t check them out in Blender. At the moment my only suggestion would be to mix in 0.3-0.45 of a translucent shader of the same color as the diffuse so that some light is able to get through the petals to the other side.
Keep up the good work!