fix alpha for tooltip colors

diff --git a/src/core/core.tooltip.js b/src/core/core.tooltip.js
index ae3e2d58aa7aa5c9a0b4f4cd34607734cd61d350..11401a0353f37a4499cc1b4d6c3a3a309c18588e 100644 (file)
--- a/src/core/core.tooltip.js
+++ b/src/core/core.tooltip.js
@@ -483,7 +483,8 @@ module.exports = function(Chart) {
                                }
                        }
 
-                       ctx.fillStyle = helpers.color(vm.backgroundColor).alpha(opacity).rgbString();
+                       var bgColor = helpers.color(vm.backgroundColor);
+                       ctx.fillStyle = bgColor.alpha(opacity * bgColor.alpha()).rgbString();
                        ctx.beginPath();
                        ctx.moveTo(x1, y1);
                        ctx.lineTo(x2, y2);
@@ -495,7 +496,9 @@ module.exports = function(Chart) {
                        if (vm.title.length) {
                                ctx.textAlign = vm._titleAlign;
                                ctx.textBaseline = "top";
-                               ctx.fillStyle = helpers.color(vm.titleColor).alpha(opacity).rgbString();
+                               
+                               var titleColor = helpers.color(vm.titleColor);
+                               ctx.fillStyle = titleColor.alpha(opacity * titleColor.alpha()).rgbString();
                                ctx.font = helpers.fontString(vm.titleFontSize, vm._titleFontStyle, vm._titleFontFamily);
 
                                helpers.each(vm.title, function(title, i) {
@@ -511,7 +514,9 @@ module.exports = function(Chart) {
                drawBody: function drawBody(pt, vm, ctx, opacity) {
                        ctx.textAlign = vm._bodyAlign;
                        ctx.textBaseline = "top";
-                       ctx.fillStyle = helpers.color(vm.bodyColor).alpha(opacity).rgbString();
+
+                       var bodyColor = helpers.color(vm.bodyColor);
+                       ctx.fillStyle = bodyColor.alpha(opacity * bodyColor.alpha()).rgbString();
                        ctx.font = helpers.fontString(vm.bodyFontSize, vm._bodyFontStyle, vm._bodyFontFamily);
 
                        // Before Body
@@ -558,7 +563,9 @@ module.exports = function(Chart) {
 
                                ctx.textAlign = vm._footerAlign;
                                ctx.textBaseline = "top";
-                               ctx.fillStyle = helpers.color(vm.footerColor).alpha(opacity).rgbString();
+                               
+                               var footerColor = helpers.color(vm.footerColor);
+                               ctx.fillStyle = footerColor.alpha(opacity * footerColor.alpha()).rgbString();
                                ctx.font = helpers.fontString(vm.footerFontSize, vm._footerFontStyle, vm._footerFontFamily);
 
                                helpers.each(vm.footer, function(footer) {
@@ -587,7 +594,8 @@ module.exports = function(Chart) {
 
                        if (this._options.tooltips.enabled) {
                                // Draw Background
-                               ctx.fillStyle = helpers.color(vm.backgroundColor).alpha(opacity).rgbString();
+                               var bgColor = helpers.color(vm.backgroundColor);
+                               ctx.fillStyle = bgColor.alpha(opacity * bgColor.alpha()).rgbString();
                                helpers.drawRoundedRectangle(ctx, pt.x, pt.y, tooltipSize.width, tooltipSize.height, vm.cornerRadius);
                                ctx.fill();