Green’s Dictionary of Slang

tally-ho adj.

(US) gaudy, ostentatious.

[US]B. Hecht A Thousand and One Afternoons [ebook] [T]he idea of Queen Bess blowing in $5,000 for a tally-ho layout to ride to the races in! Six horses and two drivers in yellow and blue livery and [...] the beribboned and painted coach bouncing down the boulevard.