一片火

Let me try a literal translation:)

一片火, One flame,

两片火. Two flames,

緋衣小兒殿上坐. A kid in pink sitting up in the palace,

烏雅飛過河, A crow flying across a river,

兔子滾下坡. A rabbit rolling down a slope ,

萬事一塲空, What will be will be,

不用動干戈. All the fuss ends up in nothing.

I've read the story. This cannot be translated.

千里草,. 何青青. 十日卜,. 不得生。

It is almost impossible for people to guess what lies behind these characters without adequate historical knowledge of 武则天. But it is really interesting to give it a try.

I have a riddle for you, "一字千金，打一字". I just ran across this riddle the last time I went to teahouse, I would like to share it with you.

one sheet, two sheets

of flame were there.

wearing in dark red, the throne seated by the child,

flying over the river was a crow,

rolling downhill was a hare,

ended up with emptiness, everything involved, 

without weapons of war, one can used.

Good translation by meaning!  The only gripe that I have is the use of "kid" and "pink".  "Kid" here is too slangy.  "Child", "little one" will be more appropriate.  緋 here is an interesting word.  The meaning here is deep red.  In ancient times, it is of the deep red to the hues of turning purple. Only nobility can use this color.  In modern parlance, most probably influenced by English, to mean scandal as in "the scarlet woman". 緋 is used to distinguish 紅 as the latter is associated with happiness, auspiciousness etc. 

In the context, both meanings are appropriate.  However, given that it came of the Tang imperial chronicles, and the underlying meaning of the poem shouldn't have the color of 緋聞茶樓滿天傳.

Good version. I would change your English slightly to a more poetic form.

one sheet, two sheets

of flame were there.

wearing in dark red, the throne seated by the child,

flying over the river was a crow,

rolling downhill was a hare,

all involved, all ended up with in emptiness, everything involved, 

without no weapons of war, one can used.

Thanks, Jeff! By the way,  "深红" is “deep red” or “dark red”？ I thought I was wrong after reading the comment for FB 5 minutes ago when you didn't put the new correction for mine. 

It seems that most knew of this riddle of the Tang Chronicles. So I shan't spend the time talking about this unless someone asks for explanation. Since this is a sort of pseudo riddle, I take a more literal approach.

一片火, One flame

两片火. Two flames [more]

緋衣小兒殿上坐. In toga purple a little one sits on the throne.

烏雅飛過河, Across the river, flew a crow

兔子滾下坡. Down the slope is a tumbling rabbit.

萬事一塲空, A myriad happenings, all in emptiness,

不用動干戈 Need not move even a single halberd.

oh, you used purple. is "toga" a kind of "robe"?

across the river,flew a crow. sounds more nice.

verb+noun is inverted sentence. (?)