Hi. check out the site's techniques articles for sizes and colors.

www.swimbait.com

As for me personally...for the ocean targeting bass and 'buts, I use mostly 5-inch baits yearound and sometimes 6-inch if I'm targeting bigger calicos along the beach or at the islands. I use 4 inch in winter when the bite is slower. I use 3 and 4 inch in the bays. Here are some of my fave colors that work for both species:

for baitfish colors 48, 37, 11, 4
for early/late/lowlight 35, 37
for bottom forage 45,49, 16

You might like how a variation of these looks better--I fish other colors too, these came to mind first.