Anyone who knows the old rhyme "Roses are red, violets are blue" will see right away that this poem is playing with it. Instead of the usual sweet setup, it swaps in "black" for both flowers, then the speaker announces, "I am a dog." The final line, "I am color blind," seems to explain the strange colors, though the logic is silly. Dogs aren't actually seeing everything in black, and the joke works because it only half makes sense.
The speaker comes across as deadpan and a little cheeky. The username, "No1UCareAbout," suggests someone who doesn't take things too seriously, or who wants to seem that way. Judging by the title, "Play time," the poem is meant as a bit of fun. The mood is light and absurd, with a hint of mock-gloom in all that black. It reads like a quick doodle in the margin of a notebook: short, odd, and happy to poke fun at a very familiar form.