Calculating Field Specific Averages From Records In Separate Tables

Let's say I have a table sort of like this one: [URL] .... (Table 1)

What I want to do is make another table that references the first table: [URL] ... (Table 2)

I want the cells in the Average field in Table 2 to calculate an average of all the values for records in Table 1 with Color fields that correspond to the Color field in Table 2 (this makes a little more sense if you look at the pictures). I could do this in Excel, but then problems would arise whenever I would add a new entry to the database, or re-alphabetized the data, since Excel math is depends entirely on the positions of cells, and I want these averages to be continually calculated correctly and to change whenever I add related records to the database.