use original pattern colors when alpha is one

Author: archmoj

src/components/drawing/index.js

@@ -412,8 +412,9 @@ drawing.pattern = function(sel, calledBy, gd, patternID, shape, size, solidity,
     var patternAttrs = {};
 
     var fgC = tinycolor(fgcolor);
-    var fgRGB = Color.tinyRGB(fgC);
     var fgAlpha = fgC.getAlpha();
+    var fgRGB = fgAlpha === 1 ? fgcolor : Color.tinyRGB(fgC);
+
     var opacity = fgopacity * fgAlpha;
 
     switch(shape) {
@@ -557,8 +558,8 @@ drawing.pattern = function(sel, calledBy, gd, patternID, shape, size, solidity,
 
             if(bgcolor) {
                 var bgC = tinycolor(bgcolor);
-                var bgRGB = Color.tinyRGB(bgC);
                 var bgAlpha = bgC.getAlpha();
+                var bgRGB = bgAlpha === 1 ? bgcolor : Color.tinyRGB(bgC);
 
                 var rects = el.selectAll('rect').data([0]);
                 rects.exit().remove();