First of all... this will be boring to experienced flyers, as this is common practice with most guy's fuel lines.
I use this set up on ALL the planes I have owned.
Use a different color fuel line for the fill line and the pressure line from the muffler. A lot of ARF's come with the same color. They can accidently get switched!! (don't ask me how I know) I use pink on all the pressure lines, and the common blue for the fill lines. Also.. after defueling the plane, (you did de-fuel...right?), pull the lines at the muffler and needle valve as if you were fueling. Connect the two with a 1" piece of brass tube to "seal" the tank for storage or transport. Not all the fuel will pump out and it could absorb moisture, find it's way out if the plane is upside down, or, become gummy with time. If you new guys don't want to change lines by pulling the tank just yet, it can be done very simply. Buy fuel line connectors, cut off about 1" or 2" of blue from the pressure line, and replace it with pink.
NOTE...... DON'T use brass tube here. The true connectors have barbs on them to secure the line. Also... some connectors have a smaller ID. These are usually used for air lines?? I am not sure... but I think Foremost is the brand I bought with the larger inside diameter. Try to keep the connector in a spot where the line is straight and not bent around something. (less chance of coming apart).
.....lownslo.......Bob

i use dark blue and light blue works good but my lines break every other week.......i've been flying for 3 weeks so far this year.

For me: yellow/red, or blue/red.

Yes, I use colour coding too - but I always make sure the fuel line is a transparent colour. This is to ensure that there are no air bubbles in the fuel line - leaking tanks or ruptured lines probably happen to us all sooner or later.

Why are your fuel lines breaking?? I've had one develop a slight leak over time but....?
Dennis-

the line was pushing against the nose gear wire and breking it but i fixed that now.