Locate legacy Pantone swatch files (e.g., "Pantone Solid Coated.ase"). Step 2: In Illustrator, go to Window > Swatches . Step 3: Click the hamburger menu (☰) in the Swatches panel > Open Swatch Library > Other Library . Step 4: Select the .ase file. The library will appear and be usable in your current document.