What does the yellow speech contain? Also the truth?

This is about the 1998 movie The Celebration (Festen) from Thomas Vinterberg.

Helge turns 60 years old and invites many people to his large hotel in the Danish countryside. His oldest son Christian, who runs two restaurants in Paris, also comes. Not long before, Christian's twin sister Linda had committed suicide and Helge asks his son to give a speech, because he wouldn't be able to hold back his tears.

At the dinner, Christian stands up and shows two cards, a yellow and a green one.

Christian: I should like to propose the first toast, it being my duty as the eldest son. Correct, Helmuth?

Helmut: Absolutely.

Christian: But first, a speech. I've written two, Father. One is green, the other is yellow. You choose. Green? Yellow?

Helge: I'll take the green.

Christian: The green is an interesting choice. It's a kind of home truth speech.

_{Note: Helmut is the toastmaster.}

Then, Christian holds the speech, revealing the family secret:

Christian and Linda were sexually abused by Helge during their childhood.

Here's the scene (source of the dialogue above; to avoid spoilers, don't watch any further than 0:40).

Is there any indication as to what the yellow speech contained?