 
       /// RGBA_FROM_P3{152, 101, 51, 255}
 
-      let (r_p3, g_p3, b_p3, a_p3) = brownP3.rgba8Bit!
-      let (r, g, b, a) = brownRGBA.rgba8Bit!
+      let (r_p3, g_p3, b_p3, a_p3) = brownP3.rgba8Bit
+      let (r, g, b, a) = brownRGBA.rgba8Bit
 
       XCTAssertTrue(r-1...r+1 ~= r_p3)
       XCTAssertTrue(g-1...g+1 ~= g_p3)

    do {
      let black = Color.black // 0.0, 0.0, 0.0
      XCTAssertNotNil(black.rgba8Bit)
      let (r,g,b,a) = black.rgba8Bit!
      XCTAssert(r == 0)
      XCTAssert(g == 0)
      XCTAssert(b == 0)

    do {
      let red = Color.red // 1.0, 0.0, 0.0
      XCTAssertNotNil(red.rgba8Bit)
      let (r,g,b,a) = red.rgba8Bit
      XCTAssert(r == 255)
      XCTAssert(g == 0)
      XCTAssert(b == 0)
