People who cannot distinguish between colors are said to be color-blinded.

不能分辨色彩的人被称作色盲。

youdao

Clearly, either these customers cannot distinguish butter from margarine or they use the term "butter" to refer to either butter or margarine.

显然，这些顾客要么是分不清黄油和人造黄油，要么就是用“黄油”这个词来指黄油或人造黄油。

youdao

People who cannot distinguish between colours are said to be colour-blind.

不能分辨颜色的人被称为色盲。

《新英汉大辞典》

An Australian or a Texan cannot distinguish between a Loire wine and a Bourgogne.

BBC: NEWS | Programmes | Newsnight Home | The taste of French patriotism

Lenders who cannot distinguish good borrowers from bad become less willing to lend to anyone.

ECONOMIST: A liquidity squeeze

The findings demonstrate the volunteers cannot distinguish between wines by taste alone, the organisers of the test say.

BBC: Cheap wine 'good as pricier bottles' - blind taste test