The secret to any colour, but more so with lighter colours is preparation - ensuring that the paintwork is fully decontaminated...and this cant always be seen by the eye. Bonded contamination that regular washing wont remove; tree sap, iron particles, etc

Dry or let drip near dry
De-tar, followed by a rinse, dry or let drip near dry (spray on, allow dwell for a few mins, rinse off)
De-iron, followed by a rinse (spray on, allow dwell for a few mins, will turn purple on contact with contamination, rinse off)
Claybar the car, followed by a quick wash and dry
Apply a wax of choice

90% of the battle is in the work above, the final 10% is in the choice of wax / sealant

Bilt Hamber Finis-Wax is a superb choice -
Available in 50ml or 250ml pots - gives a really nice pop on lighter colours, beads really nicely and has good durability for a wax. Apply in thin layers, makes it easier to apply and buff off (not that its difficult to work with) and apply a 2nd about 3hrs later (in current conditions)