The largest of the smaller openings is 3 x 2, The large oval is 6.25 x4.5" Choose from the COLOR LIST BELOW or you may request colors of your choosing and I will let you know if I can provide them for you. The third picture shows our archival stock mats. COLOR LIST: They are from left to right: Soft White, Dark Green, Pure Green, Spring Green, Brown, Tan, Dark Chocolate, Cream, Sky Blue, Royal Blue, Silver Blue, Navy, Bright White, Red, Medium Grey, Light Grey, Black and Pink as show as background. Not shown but also available are silver and gold. Archival mats are either Bainbridge or Artique. Fabric matting is also available. Fabric matting adds an elegant touch. RETURN POLICY All are mats are individually custom cut "one by one" for your order specifically. We do not stock them already cut . For that reason they cannot be returned but if you have a problem please contact us and we will see what we can do to resolve your problem. CHOOSING THE CORRECT MAT SIZE When purchasing a mat for a picture frame be aware that your standard frame should measure at least 1/8” larger than the size of the mat you purchase. In other words an 11 x 14” frame should actually measure at least 11 1/8” x 14 1/8”. All are mats are individually custom cut "one by one" for your order specifically. We do not stock them already cut . For that reason they cannot be returned. But please contact us if you have a problem and we will see what can be done.