add color filters to your images within your Google Slides. To add these Instagram-like filters to your images insert your images as you always have. After inserting an image click on it and you will see a new "image options" menu in the Slides editing toolbar. See my screenshots below for a visual of where to find the new "image options" menu.
In addition to the color filter options, you can now adjust the transparency, contrast, and brightness of the images that you insert into your Google Slides.