Fair enough.I must have elaborated on that a bit more. What I meant was that always bat first unless there's heavy overcast conditions and you expect the pitch to have juice in it. Most often, the pitch would look green but the weather would be fine and batting first would be a better option there despite the greenish looking pitch.
Asian teams often do this mistake of bowling first whenever they encounter a green tinged pitch.
Pakistan opted to bat first in Headingley last year and lost the match, allowing England to win their first test match in 8 matches.
A description of the conditions just prior to the match .....
Headingley has a reputation for favouring the seamers which is still just about justified although the pitch has proven more batsman-friendly in recent times. In early season, however, there could be more assistance to the quicker men than has become usual, particularly given the rain which has been around in Leeds in the lead-up to the match. Wet weather is expected on the first day as well but the rest of the match should be dry.
In the first Test at Lord's England won the toss and batted first but Pakistan won the match. It seems the home team didn't make the mistake that you described above but still lost.
On a cloudy morning and faced with a green-tinged surface, Root opted to bat on winning the toss, only for his team to be undone by a Pakistan pace quartet that exposed their shortcomings.