What color horse will you get if you breed a strawberry roan stallion with a blue roan mare?

If either horse is homozygous for roan the foal will be roan, if both are heterozygous there is a 75% chance that the foal will be roan.

If by strawberry roan you mean the stallion is a bay roan as opposed to a chestnut roan, we can surmise that the stallion is Rn-A-E-

The mare is Rn-aaE-

The base color of the foal, without regard to whether it is roan is as follows

If the stallion or mare is EE at the extension site they will produce either a bay or black foal...since the stallion is bay he could be AA (only bay foals) or Aa which will produce 50-50 bay or black with this mare.

If both the mare and the stallion are Ee at the extension site there is a 25% chance of a chestnut foal.