Adobe CC (formerly Adobe Kuler) is useful for generating colour schemes from screen shots of, say, a logo or photograph.
This free, online dataviz tool by Adobe allows users to match the existing colour palettes of organisations they are working with by uploading an image of a logo or a website screen shot. The tool can automatically pick colours based on desired attributes, such as "bright" or "dark", or users can manually select points the colours in the image by dragging the selection circles around.
To find the colour information of their selected palettes, users can click on the coloured circle to to right of the screen to be taken to the Colour Wheel, which shows the colours' RGB and HEX attributes. Users can also save their palettes (requires a free Adobe account) and download them as .ase files.