Colours as you've never seen them before...
I believe that everything has its own colour. Each person's idea of what this colour is is different and not everyone will necessarily be able to find that colour. It is my view that we see the colours in our mind whilst we are thinking of the word/letter/object/etc. Each interpretation is different and a lot can be influenced by how we feel about that particular thing (ie Lou sees Monday as grey because she dislikes coming back to school) or by something that the word/letter/object/etc. reminds us of (ie we see Physics as purple because the revision guide is purple and we associate the two together). These colours can change over time as our ideas and our situations change, but there will be some that never change (ie Wednesday being pink for me).

Colours of days...
My friends and I all seem to have very different views on what colour all the days of the week are. My view is:
Monday - Yellow
Tuesday - Orange
Wednesday - Pink
Thursday - Dark Green
Friday - Navy/Purple
Saturday - Pale Blue/Lilac
Sunday - White/Pale Grey
How about you?

And while we're at it...
How do you see the letters of the alphabet?
A - red
B - blue
C - yellow
D - green
E - yellow-green
F - purple
G - brown
H - red-brown
I - pink
J - crimson
K - turquoise
L - orange
M - red
N - royal blue
O - green
P - red
Q - gold
R - dark green
S - silver
T - yellow-brown
U - red-orange
V - pale grey
W - white
X - green
Y - lilac
Z - black
And numbers?
1 - red-orange
2 - yellow
3 - orange
4 - brick red
5 - dark green
6 - blue
7 - pink
8 - red-brown
9 - black
0 - white

Check this one out for colour...