Questions re cold-water dyeing...

OK, since we have expert peoples on here who've done this before and
know what they are doing!!! I have a question...

I've been playing again today and have another 5 pairs of colours
gently stewing in the bathroom. But as I had a small amount of dye
left over, I had a go at space-dyeing an odd piece of plain white
calico.

Its come out really nice in the centre, but the edges are too burgandy
and dark blue for my liking - if I over-dye with pure bright yellow
will it change the overall colour of the piece? or should I just drop
spoonfuls around and about?

How about if I used bleach and sprinkle that strategically over the
dye - I know from my City & Guilds work that the bleach will take the
dye straight out, so can I then over-dye with the yellow to get a
brighter effect?

I appreciate that I could try all these options to see what happens
myself, but the piece does look rather yummy and I'm interested to
hear what other people have done before I start re-inventing the
wheel... "OK since you're so clever, you tell us what colour it should
be..."

I also have a piece of WOW fabric that I tried space-dyeing, but its
come out totally purple - we used far too much Raspberry and Turquoise
and the whole thing is far too dark for my liking - can this be
rescued at all?

Suzie B
--
"From the internet connection under the pier"
Southend, UK
http://community.webshots.com/user/suziekga