Highlights grown out - pics

Hello!  I have been having higlights done to my hair for about 6 months now.  When I first had it done, I dyed my hair brown for a base color (It's normally brown, but I had at home highlights in it and I just wanted a fresh pallete) and had my stylist do foil highlights.  It looked wonderful!  My second time with her she placed very fine foils along the grown out roots to try to "even it out"  however,you can still see a very distinct line of grown out brown hair (with an occassional streak of blonde)  in comparisson to the bottom half which is pretty much all blonde now.  My question is:  I am going to be getting foils again in a few weeks.  Should I dye my hair brown again for a base?  I really love the color I have now, but I'm worried that this "brown line" will just get longer and longer.  Should I ask my stylist for chunkier highlights this time?

(the red text says: brown line)