The Poodle, the toy variety, is used in this case, can be found in a wide range of colors
…These vary from black to red to beige and just about every color in-between. So, what happens when the 2 different breeds are mated is that the white coat of the Maltese will “mix” with the strong colored coat of the Poodle. In many cases, genetics will come into play and the white will fade or lighten the darker, solid color.
This means that is the sire or dam is red, an apricot
puppy is likely. If the sire or dam is black, a blue may be produced, since blue is a diluted black, or the coat may be more of a grey.
For a true, solid and strong brown Maltipoo to exist, luck plays a big role. When the fetus is developing, genetic instructions would need to pull the brown and either ignore or give very little attention to any white or cream colored coat.
In some cases, a breeder may dub a Maltipoo to be brown, when in fact the pup is a tan, beige or other watered down hue; though these colors - in their own right - are just as lovely.