My 2 cents guys....
First, so many games over so many years. There are many differences in inserts, when making comparisons......
First, clean your inserts on older games. Q-tips, and cleaner.
The second difference is older games inserts are now somewhat "frosted" from ball wear, compared to new inserts, so a major appearance difference here, and the same title from game to game based on this wear.
Electrical current in your house or game has an affect as well, they vary. Daytime viewing, ambient lighting and ones eyes.
The size of the insert, the color, the age, and the manufacturer.
Lastly is your taste. Muted, average, or over the top.
Some small inserts do well with a single LED, frosted for less brightness, or clear for brighter.
After all, the insert is a lens. So if you have an older game with worn inserts, you may want a brighter bulb. Where as someone with a less routed game, will choose different.
A frosted single SMD is an excellent choice. It may be that you want brighter, so a single SMD no lens. As the insert grows in size, you may want a 2-SMD or 4 SMD.
Color insert matching is correct as well as with white.
So a red insert can get red or white.
Amber insert, white or amber,
yellow...same.
White inserts are where you personalize your game...Cyans, Purple, Green, multicolor, etc....
I find that having the 2 types of LED's, frosted white and clear are an inexpensive and needed bulb in my box. Just for cost. One can use all frosted SMD bulbs for a nice glow....others 4 smd everywhere to blind.
We all have different tastes, and different ideas as to whats right for ourselves.
Have the variety, experiment, and enjoy adult pinball Lite Bright!