I just started to use watercolor and got a set of 6 Schmincke Horadam watercolors. I decided to get some more and looking at a color table I found out that colors have a lightfastness categorization.

I thought that all artist grade watercolor was at top of lightfastness grade.

However, it says "The rating of lightfastness as a 5-star-system is based on blue wool scale. This allows a more precise differentiation especially in the more lightfast categories."

Few colors have a 1/2 star on lightfastness scale and some new colors have "Without evaluation of lightfastness."

Should I consider the lightfastness star when choosing color or bottom line is more than enough?

What's the minimum star rating I should look for to make sure it has durability over time if kept indoor and not direct sunlight exposition?

EDIT 1:

add link to color table with lightfastness stars