The Pastel brush set are a Natural Blend brush type. They are in the Brush Palette and the Basic brush set in the Brush Library.
Smear and Blur appear in two places in SketchBook Pro Desktop. These brushes are not available in SketchBook Pro Mobile. Tap the arrow, scroll down to Colorless and select it to change the properties of the brush into a Colorless brush. The Brush Types menu is below the example brush stroke. On Mobile, in the Brush Library, tap Settings.
