Try a Bright Green.
I have Sight Bright Green sight paint on the upper half of my front sight on my 638, 64, and 625 3". It works great outdoors.
For low light a tritium front sight is probably THE answer.
My 2 Cents
My recomendation is to shoot as lite of loads as you can get for practice with a J Frame until you get comfortable with it. When you start to feel confident in your ability shooting it, add 5 rounds of warmer ammo (Still Standard Pressure) the last 5 shots of your range session. When you get comfortable with the last 5 rounds of warmer ammo progress on. From this point you might want to add 5 rounds of +P after the warmer ammo.
Get some Snap Caps for additional Trigger Time. Using Snap Caps you are: Building up your trigger finger.
Breaking in the gun more without the wear and tear of firing it.
Getting quality time in with the gun without recoil being a consideration, or ammunition being an expense.
(If you flench dry firing you know you did it. Recoil can hide a flench with live ammo)
You could get 2 sets of snap caps and do a practice reload using them also.