Merle is a pattern, and as such it can appear on any base color (chocolate, black, blue, orange). With the many colors Poms come in, this leads to a huge number of possible combinations.
Variations – Merle can dilute black and chocolate each time it occurs including: black, black and tan, chocolate and tan, dilute black (blue), blue and tan and dilute chocolate (beaver), sables, brindles. Merling can occur in the color areas of parti-colored dogs. Other colors (red, orange, cream) show little visual effect.
Blue Merle
The merle pattern on what would have otherwise been a black pom is referred to as Blue Merle. If no other genes are at play they appear to be black with patches of blue/grey.
Blue Merle Adult 
Blue Merle 8 wks 
Blue Merle 6 mos
Merle with Other Patterns
In addition to appearing on any base color, merles can also appear in combination with other patterns. For example a blue merle & tan will have white markings, tan markings and the merle pattern on the same dog. This pattern combination is frequently seen in Shetland Sheepdogs and Collies. You can also have tan markings on a merle pattern without white, resulting in a blue merle & tan.
Blue Merle & Tan Parti Adult 
Blue Merle & Tan 6 mos 
Blue Merle & Tan 8 wks 
Blue Merle Parti 8 wks
