first blush, at

at first blush

Upon first seeing or considering something. At first blush, I thought the house was great, but the inspector's list of problems changed my opinion. The contract did seem favorable at first blush, but it eventually cost me a lot of money.
See also: blush, first
Farlex Dictionary of Idioms.

at first blush

Also, at first glance or sight . When first seen. For example, At first blush we thought it was an elegant restaurant, but it soon became obvious that it was hardly the place for a special dinner , or At first glance the contract looked just fine. All three phrases date from the 1300s. The noun blush is used with the obsolete meaning "glimpse" or "momentary view" and in this idiom has nothing to do with showing embarrassment. Also see love at first sight.
See also: blush, first
The American Heritage® Dictionary of Idioms by Christine Ammer.

first blush, at

Without prior knowledge; at first glance. The earliest use of this expression dates from the sixteenth century, when blush meant not a reddening of the cheeks with embarrassment but “glimpse.” Thus, “Able at the first blushe to discearne truth from falsehood,” wrote Philip Stubbes (The Anatomie of Abuses, 2:7) in 1583.
See also: first
The Dictionary of Clichés by Christine Ammer
See also:
  • at first blush
  • blush
  • at first glance
  • at first glance/sight
  • be first out of the box
  • first in, best dressed
  • first refusal
  • refusal
  • give (someone) the first crack at (something)
  • have (the) first crack at (something)
References in periodicals archive
At first blush, at least, a Trump presidency promises everything that AIPAC, America's largest pro-Israel lobbying group, could ever wish for.
It explores the purpose and promise of more effective engagement of those stakeholders who--at first blush, at least--appear to express the deepest resistance to the productivity agenda: faculty.