colouring a treeview recursively

[L Melville]

Hi,

I have a treeview with quite a lot of nodes in it, what I want to do is
colour a particular node red if a certain criteria is met, and also colour
all parents red, right back to the root node. I have been thinking about
this and cannot think of an efficient way of doing it as the tree may need
to be re-scanned at frequent intervals. the tree would obviously need to be
scanned in its entirety when first loaded, and also a section of the tree
(from a particular root node) when a node is added, deleted or altered.
Here is how a section would look;-

red
- black
- black
- red
- red
- black
- black

any node underneath a reddened one that do not meet the criteria would not
need to be red since the parental colouring is only to signify that a red
node exists underneath it.

does any one have an easy and efficient way of doing this, or something
similar?

thanks in advance
lee