Starting from the title I expect the poem to be about the celebration, but I don't know the celebration of. The title is very interesting because it refers to the number 8 which completes the word "celebrate"  

The poem is arrenged into 13 stanzas, with 8 verses each and there isn't regular rhyme pattern.

The first stanza is a celebration of the world's diversity against discrimination, in this stanza the speaking voice invites the reader to  embrace the diversity.

In the second stanza the speaking voice tells why we have different colour of skin and refers to melanine, so it is says that it's really stupid to discriminate someone for their skin colour , because the only thing that changes is the quantity of melanine.

The third stanza is about God and religion, the speaking voice invites to celebrate the different cults and faiths of each human being. 

Then the first stanza is repeated again.