A few years ago I had a freelance job and part of it was drawing a fruit tray. I did the basic shapes in Illustrator, brought it into Photoshop to do the final tweaks and make it look real, but I had a hard time getting the color of the inside of the watermelon exactly right. It was either too pink or too red. Or not pink or red enough.
One trick I use when I’m drawing something that needs to be fairly realistic is to find a photo of it online (if I don’t have a photo) and use the photo as a color palette. I found a small low resolution photo that was the right color, and pasted it into a new layer. Then I used the eyedropper tool to select the colors I needed from the photo to paint my watermelon the right color.
Another thing I do sometimes is give myself a little extra canvas beside what I’m working on. Whenever I pick a color to use, I use a big brush and paint a splotch of that color on the side. It’s like having a palette of colors to paint with, just like a ‘real’ artist! 😉
That way I don’t have to remember the colors I’ve used or try to select a color that’s on a layer with effects. My colors are there and I just use the eyedropper to pick whatever color I need from the other image.
Also, you can create a custom palette from an existing image. First you have to index the image to its own palette. Just open the image and go to IMAGE>MODE>INDEXED COLOR. Note – if the image is CMYK you need to first convert it to RGB, then to Indexed.
When the modal box opens, choose Palette:Local (Perceptual), Colors:usually 256 but you can do less if you like, Forced:None, Transparency:unchecked, and Dither:None. Click ok and your image will be indexed to a palette.
Now if you click on IMAGE>MODE>COLOR TABLE it will open the palette you just created from your image. Cool huh? As you can see, this gives you a much larger palette to work with than my example above, but each has its uses.
If you want to save it, click the SAVE button on the right and it will save as an .ACT file. Now whenever you want to use that palette again, go to WINDOW>SWATCHES and when the swatches window opens, click the menu on the top right and choose IMPORT SWATCHES. When the browser window opens, change the file type from Swatches(*.ACO) to Color Table(*.ACT) and find the .ACT file you created, click ok, and the custom palette that you made from your image is ready to use.