Does a change in vein color from blue/purple to red indicate spider veins are shrinking/disappearing? (& treatment is working?)

I have been treating spider veins on my legs, ankles and feet mostly with laser. I've had several treatments. What I notice after treatment is a flare-up (sometimes the veins blow up/raise from the skin a bit) wherever the laser hit. After a couple of weeks it seems like I can still the veins but it's almost like they've changed color from a deep blue / purple to a more reddish/pinkish tone. Does this change in color indicate that treatment is working? Or does the change in color mean nothing?