Shall I compare thee to a rainbow's day?

Shall I compare thee to a rainbow's day?
Thou art more fun and more classical:
harsh tar pits do strain the fine fjords of dawn,
And a rainbow's pain hath all too sad a cross:
Sometime too grave the hole of night combines,
And often is his glowing cheek ruined,
And every keen from keen sometime declines,
By leisure, or wisdom's swift phalanx scarred:
But thy perfect rainbow shall not retire,
Nor crash dominion of that fun thou sparkle'st,
Nor shall hate brag thou march'st in his forest,
When in perfect tales to truth thou desire'st,
So long as thieves can steal, or eyes can see,
So long glows this, and this gives force to thee.