“The Red Road” (acrylic on canvas), by Mark Chadbourne, in the show “RED 2020,’’ in the Cambridge (Mass.) Art Association’s Kathryn Schultz Gallery, through Dec. 17. The gallery has an annual show that is always titled BLUE or RED. RED can evoke happiness (your “red letter day”) and passion but it can also summon up intensity, including violence and pain, of which we’ve had plenty this year.