Son of Mine Analysis

Son of mine
Rhyming scheme AAA..
Implies that the Aboriginal son has been hurt by racists acts against him and is looking for answers as to why he is being discriminated against because of his race.
12 lines

Colour line is the prevention of black people participating in various activities with whites. This relates to social justice because blacks are segregated and excluded from ordinary activities
My son, your troubled eyes search mine, Puzzled and hurt by colour line.
“What can I tell you son of mine?” is a rhetorical question which emphasises her confusion and frustration towards racism and discrimination.
Your black skin as soft as velvet shine;
These are the past experiences the mother has experienced in the past. This is parallel with social justice because she has been through a lot of negative times because she is an Aboriginal. She questions herself in whether she should tell him these times or not
What can I tell you, son of mine?
I could tell you of heartbreak, hatred blind,
I could tell you of crimes that shame mankind,
Of brutal wrong and deeds malign,
Of rape and murder, son of mine;
Instead of telling her son about the harsh memories, she decides to tell him about the future when one day discrimination does not exist and black and whites entwine accepting each other’s diversities.
But I'll tell you instead of brave and fine
When lives of black and white entwine,
And men in brotherhood combine--
This would I tell you, son of mine.

Hm... yes, it has got a regular rhyming scheme, but with the exception of “blind” and “mankind”. It’s got rhyming couplets. The protagonist is an Aboriginal mother who feels helpless towards her son, but she doesn’t want her son to grow up in fear for himself because of all the racial issues, so instead she, like you said, tells him to hope for a future where everyone can live harmoniously regardless of their race. So that means the theme, or the message, of the poem is about moving forward and forgetting the past to create a positive future between Indigenous and white Australians. The mood is painful, I guess, because it’s painful to read or imagine a poor child being hurt or discriminated because of his race. The “son” could be a metaphor for future generations of indigenous people (I guess, I’m not really sure, I made it up, but it makes sense I will admit.)