You could just as easily crate a table in your word processor. You could use headings such as date purchased, price, brand, color, MFG code, national color code (e.g., FS or RLM#), type (enamel, spray, acrylic), used on (what models were painted with this color) Mix with X to make Y, (two sub columns), matches (what other color brand/color matches it,), highlight with, shade with, etc. then use the table function to sort by any of these columns.
No matter how you do it, you're going to have to maintain this in a word processor, spreadsheet or database. How elaborate or simple you want to make it is up to you.