Prompt number twenty-nine, "spectrum."

I went Hard Mode on this prompt, as the term has a few different meanings, all of which bear weight to me.

A rainbow forming in the sky in the midst of a rain shower (especially on a spring day) always brings me joy, even if I know it is ephemeral. The moment it forms, and the moment I look at it -- these stay with me forever. I have captured some pictures of rainbows and double rainbows in my time before they disappeared. As such, I've made it a tender song, to express that ephemeral joy and brightness, and also the sad understanding that it physically doesn't last -- but also the hope within me that it points towards things that do last.

The rainbow is, of course, the quintessential LGBTQ+ symbol; I am part of that community. I also cherish its Biblical meaning where God placed a rainbow in the sky as a promise to Noah that there would be no cataclysmic, species-ending floods in the likes of Genesis: the rainbow has since had a special place in the hearts of Christians at least (if not also other people of the Book) as a sign of God's promise, hence the title, "a promise in the sky."

And -- this is where Hard Mode kicked in -- from before that challenge I kept a practice of marking certain instrument families with different colours. I made sure to use each colour in the spectrum when composing this, but because I'm terrified of even agitating the neighbours, I've had to rely on a MIDI guitar and various VST percussions instead of playing my own strings and percussion. So, in order of spectrum colours:

Red: cymbals, windchimes
Orange: bowed strings
Yellow: horns
Green: piano, harp
Turquoise: melodic synth
Blue: guitar
Indigo: basses
Violet: piccolos, flutes, oboe, bassoon
Magenta: xylophone, glockenspiel