Hair color fades out, help.?

During the summer my hair lightens up and my hair turns to a reddish brown. About a year and a half ago I tried to dye it back to the color it is during the winter, without thw sun lightening it. The color never sticks and eventually fades. I have avoided alcohol based products and have a color safe shampoo. I know a little color fading is natural but it doea not fade it strips my lighter brown hair right bck down to the reddish light brown color I have during the summer. My hair has grown out and my natural light brown is starting to naturally highlight from the sun. I would like to know how I can fix my ends to match my roots without waiting three years for it to grow out.