Color doesn't matter.
If a tractor is around the 10 year old mark, in good condition, with reasonable to low hours, they continue to sell very well at auction. More proof of the blue variety came Friday (February 15, 2019) when the 2007 New Holland TG305 tractor pictured below, with 2,429 hours, front and rear duals, sold for $76,000 on a farm auction in southwest Ohio by my friends at Hess Auction Co. (http://www.hessauctionco.com).
$76,000 is the highest auction sale price on a New Holland TG305 since 4/2/15...almost 4 years. Here's a look at recent auction sale prices on TG305's:
Auction Prices on New Holland TG305 Tractors
* Data by http://www.MachineryPete.com
Here's link to "Tractor Specs" on New Holland TG305's: https://www.machinerypete.com/specs/new-holland/tg305/9206
The current Avg. Dealer Advertised Price on New Holland TG305's = $73,695. Here's a link to (6) for sale today: https://www.machinerypete.com/tractors/175-hp/new-holland/tg305