It was a lovely afternoon with a blue sky and a few fleecy white clouds.

那是个美丽的下午，蓝蓝的天空中飘着几朵轻软的白云。

《柯林斯英汉双解大词典》

The superintendent was in fact preparing iron ferrocyanide, a substance also known as Prussian blue, a pigment used in paints.

这种物质一个更通俗的名称叫做普鲁士蓝，是一种绘画用的颜料。

youdao

PNAS. Dark red is an increase of 0.3 millimeters per day; dark blue, a decrease of 0.3 millimeters.

美国国家科学院院刊.深红代表每天0.3毫米的增长；深蓝代表0.3毫米的下降。

youdao

The watch's display comes in three natural colors -- we know red and green are on deck but the third remains a mystery (though blue seems a safe bet).

ENGADGET

Rather than remembering each pixel value as an address and three values for red, green, and blue (RGB), a program can check and discover that a whole region of the screen is the same color for the moment and simply say, for all the pixels between these two addresses, set them to these three values.

FORBES: Density Of Meaning: Creation As The Flip Side Of Memory

There shall be freedom of transit for French goods through Haifa and by the British railway through the brown area, whether those goods are intended for or originate in the blue area, area (a), or area (b), and there shall be no discrimination, direct or indirect, against French goods on any railway, or against French goods or ships at any port serving the areas mentioned.

BBC: Map detailing the Sykes-Picot agreement