Beat butter at medium speed with an electric mixer until fluffy; add powdered and granulated sugars, beating well. Add eggs, oil, vanilla, and lemon juice, beating until blended.
Combine flour and next 3 ingredients; gradually add to sugar mixture, beating until blended.
Shape dough into 1-inch balls; roll in colored sugar, and place about 2 inches apart on lightly greased baking sheets.
Bake, in batches, at 350° for 9 to 11 minutes or until set. (Do not brown.) Remove to wire racks to cool.
Chocolate Kiss Cookies: Omit colored sugar. After baking, immediately place one unwrapped milk chocolate kiss in center of each cookie, and cool.
Peanut Butter Cup Cookies: Omit colored sugar. After baking, immediately place an unwrapped miniature peanut butter cup in the center of each cookie, and cool.
Lemon Cookies: Omit vanilla and colored sugar. Increase lemon juice to 1/4 cup, and add 1 teaspoon grated lemon rind to dough. Proceed as directed.
Lemon Thumbprint Cookies: Prepare Lemon Cookies, and press thumb in center of each cookie to make an indentation. Bake and cool as directed. Spoon 1/2 teaspoon raspberry jam in each indentation.