Making a trendy vintage effect in Blender is easier than you think. We can get some great results with just a couple of nodes.
Jump into the compositor and activate it (click “use nodes”). Use the Render Layers input node, or add an Image or Movie Clip node. Let’s add a “Hue Saturation Value” node and lower the saturation to about 0.5. Note that the values I’m giving here are in ballpark, you’ll want to tweak them to your images.
Add a Mix node and plug the result of the previous node into it. Set it to difference, choose a highly saturated color for the second image input and lower the factor to about 0.1 or 0.03. This will give you a quick color cast.
From here on you can add a color balance or RGB curves node to fine tune colors and get some contrast back. Personally I like to use the Hue Correct node.