The sun was radiant in a clear blue sky.

湛蓝的天空阳光灿烂。

《牛津词典》

The sun blazed down from a clear blue sky.

耀眼的阳光从清澈蔚蓝的天空中照射下来。

《牛津词典》

The sun dances on blue mountain lakes.

灿烂的阳光撒满在湛蓝的湖面上。

youdao

This was because all you could see was the very blue sky and the very hot sun.

VOA: special.2009.01.14

Maybe it could refer to either the poet or the sun throughout the entire line, if you think of the mantle blue as being the actual sky that the sun is able to twitch over his shoulder.

或者两者皆可,从整句的行文看来，如果你们把蓝色的丝巾看作是真实的天空的话,那么太阳的确是能够在他的肩上轻轻颤动。

耶鲁公开课 - 弥尔顿课程节选

Often referred to as the jewel of the Caribbean for its grandiose colonial architecture, blue waters and sun drenched squares, Cartagena in Colombia combines old school elegance with a vibrant Latin soul.

FORBES: Cartagena Bay - Colombia

The mountains shimmer blue when the sun hits the eucalyptus vapors from the trees, at night, the dense star patterns of the Southern Hemisphere sky also shimmer in the clearest skies, and crossing the path to your cottage at night, you may well encounter a wombat, wallaby or kangaroo the 4000 acres are filled with them.

FORBES: Australia Ups Its Luxury Level With Posh Hotels And Nature Retreats

When I see the sun, blue sky and feel balmy breezes on my skin, my inner voice of resistance looses its strength.

FORBES: NYC Psychiatrist and Hemingway On The Benefits Of Exercise On Work And Depression