In a stand mixer or with a hand mixer, beat the softened butter until smooth and creamy, about 2 minutes.
Add 2 cups of the powdered sugar and beat on low speed until incorporated, about 1 minute. Add the remaining 2 cups powdered sugar and beat again until fully blended.
Add the almond extract, milk/cream and salt. Beat on medium speed until fully combined and smooth.
If desired, mix in a few drops of food coloring until you reach the desired shade.
Increase mixer speed to high and beat frosting for 3-5 minutes until light and fluffy.
If frosting is too thick, beat in more milk/cream a tablespoon at a time until desired consistency is reached. For thinner frosting, add more powdered sugar.
Use immediately or store frosted treats in the refrigerator. Frosting can be stored in an airtight container in the refrigerator for up to 1 week or in the freezer for up to 3 months.