Imagine you went into a paint store and ordered an off white paint. The guy mixing it put various squirts of pigment into the can, according to the formula. But it's taking a long time, and the clerk says "sorry, I had to change the white pigment cartridge, alright, 142, 143, 144" plunging the pigment lever full travel everytime.

To spare the arms of those workers, they have different bases of paint. For the off-white your guy would use base 1, which already has 150 squirts of white pigment in it, in our example. The base 2 might already have 60 squirts and the base 3 already has 10 squirts. The base 4 has none.

The paint chip swatches will have a code that says which base they start with and how many squirts of each pigment.

So you will need to look at Glidden paint swatches and ask an employee to tell you how to decode which base a swatch uses.

You're going to find all colors which use that base will have a lower to midrange lightness. For instance olive drab or battleship gray or bright blue might use that base.

It will really help if you like bright or deep colors!