coloured a greyish yellow

(idiomatic) actually, in truth

An irresponsible or carefree period has ended; it is time to be serious or take responsibility.

Events that have already taken place cannot be changed and actions that have already been committed cannot be undone, so it is best not to dwell on them.

One's life has reached its end; one is dead or soon to die.

(followed by "or") Is it a situation of my own imagination (or ...)?

Synonym of two's company, three's a crowd

(idiomatic, mildly insulting) One lacks good taste in aesthetic or cultural matters.

(informal, especially as a question) Used to indicate multiple things are difficult to tell apart

(set phrase) The situation, behavior, or opinion of a person or group has changed considerably; the circumstances or characteristics of something have changed considerably.