Iam having elocution competition on the topic life is a rainbow which also include black

Two meanings i found is that life includes all aspects from red anger envious green and elated yellow...etc all though these aspects are easily visble in life much harder to percieve is the desolate depression people harbor. This is the hardest to percieve, but is apperant in everyones lives as it is in a rainbow. Instead of supressing this from view, it needs to be accepted as a part of life. Another view could do with racism (ehhh).