Step One
Play a game with the pupils. Name a colour, and give them a set amount of time to list as many things as they can that have that colour. So for example, you might say 'green', and pupils might write 'frog; grass; tree; snot, etc. If you are into gamification, you might make this activity into a competition.
Step Two
Use some of the ideas generated in the previous activity to model some similes for the class, e.g.: 'as green as a....', 'as red as a.....'. Use this as an opportunity to discuss which are the best ideas, and how to make the similes more interesting/exciting.
Step Three
give out lots of sheets of coloured paper - as many different colours as possible placed on each table. Children can write colour-based similes on the sheets of paper, according to which colour paper they have been given.
Step Four
Share my poem 'Fireworks', below. In groups, children cut out the similes, and stick them onto a black backdrop, so as to form the shape of a firework in the night sky. They can then practice performing the pieces, and you have some lovely collaborative shape poems to display.
Fireworks
A
dash of red
A
splash of blue
A
splodge of green
and
a twinkle of gold.
A
streak of white
A
stripe of pink
A
smear of yellow
and
a sparkle of silver.
Somewhere,
a happy child
is
flicking paint
across
the sky.