A Robbery in the Dark
Last night, I witnessed a robbery. Several men dressed in black suits held up a truck transporting a rare mineral. (Which mineral?) They had guns and dogs. They rode horses under their buttocks. I thought they must have been professional robbers because their outfits were so perfect, and their horses' coats were so bright and shiny.
Down to the wire (Sorry, that makes no sense at all) Eventually, four heroes came here arrived. They prevented the robbers from leaving, with their magic bolts (I don't understand what you mean). I used my mobile phone to take a picture of the scene, then And I ran away like a clever hare.
If you only describe the colour of a person's clothes, then <em>in [colour]</em> is all you need. Think of <em>Lady in Red</em> and <em>Men in Black</em>.
"They rode horses under their buttocks," just sounds silly. Sorry. You could write, <em>They were sitting astride horses</em>.
A <em>horse's coat</em> is the colour of a horse, ie. its body hair colour.
Remember to move the tenses back for reported events. <em>Must be</em> becomes <em>must have been</em>.
I think you have some creative ideas, but several times I didn't understand what you meant.
