Since red is a complementary color of green, I changed the color of the tulip from purple to red. I did this using the magic wand tool to select the subject the added a fill layer. I then selected "darker" under layers to make it look the most natural.
This photo was created using the Gradient Maps. I chose the colors blue and yellow and then lowered the opacity.
This photo was created using the Gradient Tool and using two pictures to create a double exposed look.
This photo was also using the Gradient Tool but I chose to have another part of the second picture showing. Also, I added a vintage effect to the picture.