English idiom for 'went on to kohl it, so he/she blinded it'

Solution 1:

I think the idea of "injuring by (or while) attempting to beautify" has some similarity to "injuring by (or while) attempting to cosset or pamper"—a notion for which the most common English idiom is "kill with kindness." Here is the entry from Christine Ammer, The American Heritage Dictionary of Idioms, second edition (2013) for that idiom:

kill with kindness Overwhelm or harm someone with mistaken or excessive benevolence. [Example omitted.] This expression originated as kill with kindness as fond apes do their young (presumably crushing them to death in a hug) and was a proverb by the mid-1500s.

Elsewhere, Ammer notes that Thomas Heywood titled one of his plays A Woman Kilde with Kindnesse (1607), alluding to the same proverb.

Solution 2:

A related English phrase could be

The road to hell is paved with good intentions.

While you can't use it in quite the same way as the Arabic phrase, the sense is that well-meant actions can often cause more harm than good.

Solution 3:

"fixing something that ain't broken."

Also worded as: "If it ain't broke don't fix it".

Bert Lance, US President Jimmy Carter's director of office management and budget, popularized this expression in the late 1970's.

-See the Wikipedia article on Bert Lance.