Passing this junov@ who knows specs better. 

I briefly looked at the spec for fillStyle here:
https://html.spec.whatwg.org/multipage/scripting.html#dom-context-2d-fillstyle

It states:
On setting, strings must be parsed as CSS <color> values and the color assigned.

In the above statement, "parsed as CSS <color> values" string is linked to:
https://html.spec.whatwg.org/multipage/infrastructure.html#parsed-as-a-css-color-value

I don't really know where " red" with a space is a valid value or not.

Tested on safari, it has the same behavior as chrome

I asked this question at blink-dev@, and it is pointed out that the spec here:
https://drafts.csswg.org/css-color/#named-colors

doesn't say anything about trimming the string before matching it. So ' red' doesn't seem to be a valid string for fillStyle.

I retract my previous comments, as it is pointed out here:
https://drafts.csswg.org/css-syntax/#rule-defs

The white space should be accepted. Following is the quote:
<whitespace-token> is never indicated in the grammar; <whitespace-token>s are allowed before, after, and between any two tokens, unless explicitly specified otherwise in prose definitions. (For example, if the prelude of a rule is a selector, whitespace is significant.)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/759bba67481eed3cde4d6de8f95854dea1c1f81e

commit 759bba67481eed3cde4d6de8f95854dea1c1f81e
Author: junov <junov@chromium.org>
Date: Sat Dec 10 01:35:17 2016

Fix the parsing of colors used as canvas styles to ignore whitespace

BUG= 668584 

Review-Url: https://codereview.chromium.org/2560993003
Cr-Commit-Position: refs/heads/master@{#437710}

[add] https://crrev.com/759bba67481eed3cde4d6de8f95854dea1c1f81e/third_party/WebKit/LayoutTests/fast/canvas/canvas-whitespace-parsing.html
[modify] https://crrev.com/759bba67481eed3cde4d6de8f95854dea1c1f81e/third_party/WebKit/Source/modules/canvas2d/CanvasStyle.cpp