Magic Wand Tool
1. Open Photoshop. Open Image to work with Magic Wand Tool.
2. Select the Magic Wand Tool from Tool box (Its at the bottom right corner in the following image).
3. Once you select the tool please turn your attention to the option bar below menus and and keep the values and other aspects similar to the readings shown in the following image.
4. Click the red portion of the petal. You will notice that most of the similar colored portion of the flower is selected.
5. Press CTRL + D to deselect.
6. Click on the green area and the green colored pixels are selected. We clicked on the top left area of the following image.