Color Sketch is an app that lets you take a photo or import one from your gallery and apply a variety of filters to it, including color and contrast. You can apply these to any part of the image and then save the result to your gallery. You can use the app to create a photo collage, using your own photos and the app's templates. The templates include backgrounds, stickers, text, and more, and you can change the color and opacity of these elements. The app lets you adjust the image's brightness, saturation, and contrast and add a variety of other effects. You can apply these to the whole image or just a part of it. You can also apply the effects to a photo's color or to its grayscale version.