message: Update color variables used in AvatarStack
diff: @@ -23,7 +23,7 @@ const AvatarStackWrapper = styled.span<StyledAvatarStackWrapperProps>`
  flex-shrink: 0;
  height: 20px;
  width: 20px;
  - box-shadow: 0 0 0 1px ${get('colors.white')};
  + box-shadow: 0 0 0 1px ${get('colors.bg.canvas')};
  margin-left: -11px;
  position: relative;
  overflow: hidden;
  @@ -120,7 +120,7 @@ const AvatarStackWrapper = styled.span<StyledAvatarStackWrapperProps>`
  margin-left: ${get('space.1')};
  opacity: 100%;
  visibility: visible;
  - box-shadow: 0 0 0 4px ${get('colors.white')};
  + box-shadow: 0 0 0 4px ${get('colors.bg.canvas')};
  &:first-child {
  margin-left: 0;
  }
  