The leaves start off green but turn red later.

树叶起先是绿色，到后来会变红。

《牛津词典》

Children's faces all turn red.

孩子们的脸变红了。

youdao

Maple leaves turn red in autumn.

枫叶在秋天变红了。

youdao

They may have a high body temperature and some areas of skin may turn red.

VOA: special.2009.05.26

The leaves turn colors of red and gold and then die, falling to the ground.

VOA: special.2009.11.09

In fact, they get green tomatoes sprayed with ethylene gas to make them turn red.

FORBES: Magazine Article

"First, modern maize pollen grains are larger and turn red when stain is applied, whereas ancient grains do not, " they said.

BBC: Maize was key in early Andean civilisation, study shows

Patrick Callan of the National Centre for Public Policy and Higher Education points out that state universities experience extremes of the economic cycle pampered in good times, spurned when budgets turn red.

ECONOMIST: State universities