Visualise the pain (negativity, fragile emotions, heavy/tired energy, past hurts etc) swirling around like a muddy gooey mess.... see it all swirling, going round & round.... pretend you're stirring it up with a big stick like you're making a mud soup.
Keep it stirring til it goes totally black.... keep stirring, that pain/negativity is pitch black now, but you start to see streaks of red- lovely dark red- keep going & the red gets brighter & brighter til there's no black left. See the red being streaked with orange, swirl it round til all the red is gone & you've got a lovely bright orange.....
Keep on like this to yellow, to green, blue, indigo, violet- all the colours of the rainbow. All that mud has turned into rainbow soup! Now imagine your soup boiling over & all of those rainbow colours that you mixed in shower all over you (or over the room or whoever is nearby who might need a bit of a boost). If you want the rainbow drops can go out of the door & down the road, giving everybody a rainbow shower. Can you feel all those little rainbows running all over, all happy & smiley & full of energy?
Spend a bit of time just enjoying your rainbow shower, then gather up the droplets, see them running together & fusing into a huge stream of white light that pours all over you... and the room and everyone else- filling you up with lovely positive energy & leaving you feeling refreshed & renewed!
You can spend as long as you like on this, but also can be done quite quickly as a quick 'pick-me-up'