Assigning a value to an index in a nested table

["iain morland" <iain@...>]

Hello all,

The following question probably has a super simple answer, but I've not been
able to find a solution in the list archive or other online resources. It
may be that the search terms are just too common. So I apologise in advance
if this seems idiotically simple. :-)

I have a table that is structured like so:

example={{"Red",1,2},{"Green",3,4}}

I want to define a function that changes one of the numerical values stored
in one of the nested tables. E.g. I want to change 2 in the first nested
table to 5.

I'm already able to print the contents of that index by doing this in my
function:
print((example[1])[3])

However, I can't get this to work:
((example[1])[3])=5

...and I just can't see how else I should write the syntax to assign a new
value to the specific nested index. 

Although if I change the table so that it doesn't contain any sub-tables,
I'm able to do this:
example[1]=5

Can anyone advise?

Thanks for reading,
Iain