Painting a Rainbow

I found this a challenge- if the colours are too bright it looks more like a firework!

After some helpful tips I used linseed oil and mixed tiny amounts of colour (oil) into it until it was almost transparent. The linseed or medium soaks in like a glaze leaving a subtle muted colour which you can see through so the clouds underneath still show. Apparently this technique can be used for pebbles/rocks or sea lapping around rocks so I need to try that out next month.

Here is an example.