Both coins are the same in point values, but the red is harder to find?

I have been thinking about a coin I own, which is better to keep and hope go up in value, a red ms-65 or a brown ms-66 1920 Lincoln cent?

The population of both coins, should not change much in the near future. Most original rolls of 1920 cents, have been sent in for grading. With the demand for full red coins, if anyone had one, they had it graded, at least trying to cash in on the recent strong coin market!

The date has many red coins graded by both NGC and PCGS. So no real change in value can be expected.

The bottom line for me is the 66 maybe a little better to hold, as it is a harder date/grade to find!?

Tell me what you think?

Thanks Just coins.