Opening sizes fit one 6 1/4 x 4 3/4, two 4 3/4 x 3 1/4, four 5 3/4 x 3 1/2" photos 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 second picture shows our archival stock mats. COLOR LIST: They are from left to right: Bright White, Light Grey, Medium Grey Grey, Soft White, Pink, Cream, Red, Kelly Green, Spring Green, Forrest Green, Silver Blue,Royal Blue, Sky Blye, Navy, Brown, Tan, Charcoal, Gold, Silver, Black. Custom Sizes and orders are also available 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”. You mat will measure 11 x 14”. In addition there is a 1/16” allowance on the mat so it can measure 10 15/16” x 13 15/16” up to 11 1/16” up to 14 1/16” and still fit in your standard frame. Some less expensive frames may not have the allowance so you would need to ask for a size that is at least 1/8” smaller than the opening on the frame itself. All mats are cut one by one for you. Therefore they may not be returned but if you have a problem let us know so we may help solve your problem.