Fix this?

{UPDATE: Same day, 2 hours later} Tested Anchor pearl cotton and purple fabric backing in hot water.  Discovered the solid purple fabric was bleeding, not the pearl.  Anchor is innocent!  Ironically, I had prewashed the purple backing because it was purchased in my prewashing days (it's a non-designer fabric from local big box store, not a Kona cotton), so it could have been so much worse!  The bleeding happened mainly at the quilting because that's where the quilt top has the most contact with the backing.  Aargh!

I should have addressed this earlier, but well, I've been procrastinating.... When I washed my Penny Sampler quilt, the Anchor pearl cotton backing fabric bled onto my white sashing.  Can you believe it!?!  So not fair.



It's visible even from a distance.  See the pink flush in the lower left hand corner by the chunky pearl cotton hand quilting?



I'm sure it's coming from the pearl cotton, which is Anchor brand, color 339 - a medium gray.  It's bleeding pinky red.  I washed the quilt in the machine on cold and hung dry.  Nope, I did not use a color catcher...



Mostly it's just on the sashing, but in some places the bleeding traveled to near bye blocks.

I've never had pearl cotton bleed before.  It's definitely supposed to be colorfast.  I think this is probably a fluke, since Anchor is a good brand, but it's awful when it happens after all that work.  On the other hand, if this is the worst I have to worry about, then life is pretty good!

So, any tips on how to get it out?  I'm afraid it'll bleed more if I try to fix it.  I'll definitely use a color catcher in that load.  Spot treat with what?

p.s. for those who are wondering, I do not prewash fabrics anymore because I generally don't have any problems.  That's a decision I haven't regretted, but to each her own!