Why do we see colours? An interesting area to pursue is the idea of subjectivity in colours and what happens if you are colour-blind www.nhsdirect.nhs.uken.asp?TopicID=739AreaID=4875LinkID=39 Have a colour quiz: why is the sky blue? Why is the grass green? Why is a sunset red? Why is a lemon yellow? Why have many TV screens got tiny combinations of red, blue and green circles to make up all the colours?How are colours defined?

www.webwhirlers. com colorscolornames.asp How do we see colours? How does the eye work?www.hhmi.orgsensesb110.html

Why is light white, but mixing all paints together gives black? A good illustration of additive and subtractive colours is at www.webwhirlers.comcolorscoloursphysics.asp How do rainbows form? Remember, each rainbow is personal to the observer and moves with them when they move.

* See also this week’s poster on rainbows.