Reference photo:

Red Roan Pony "PeekABoo" Pastel Portrait, A4   Customer Comment: Great pastel! Looks just like her. Many thanks. W. Anderson , USA.

About this pony's colour (source cf. Wikipedia):

Roan is a type of coat color. To be precise, it is a mixture of white hairs together with a base coat of a darker color.

Red or Strawberry Roan starts - genetically speaking - with a chestnut (aka sorrel) base coat with white intermingled hairs. Like a with chestnut, the mane and tail are red. You will find some red roans that have so many white hairs as to have an almost pinkish tint.