Tech are a dark olive colour. Smaller fish are coloured brown.
Tench Fishing in New Zealand – Course Fish Species

The Tench – Tinca tinca Considering the extensive liberations that are known to have taken.

A fine specimen freshwater perch – Perca fluviatilis.
Perch – Perca fluviatilis – Redfin Perch Introduced freshwater fish

Perch – Perca fluviatilis – introduced freshwater fish Perch are a European freshwater fish species.