#10-14 Yellow is one of the best stretches of Tillinghast out there. Yellow and Blue were split from the original Blue to add 18 holes by Alfred Tull.
Blue, well, I'm not much for that golf course over all. The Par-3s have a sameness to them and the middles of each nine seem to fight the land. Yellow integrated the new holes better, but holes like #2 Blue are the best of the Tull contribution.
A Red/Yellow or a Red/Green 36-hole day is time well spent.
Some of the Emmet touches remaining on Green are spectacular - especially greens like #2 and #3 (#16 and #17 in the original Lenox Hills routing).
Both Red and Green feature more interesting opening and closing holes, too. #18 Green is a great short Par 4 that you can see just around the corner from the first tee of Black. Everything on that side of Round Swamp Road was done by Tillinghast.
My love for Red is well-known and I feel it's a better day-in/day-out golf course than Black because there can and will be some variety in setup from day-to-day. The routing is superb, with a giant opener and then two plateau preview holes followed by a great Par-3. The feeling of getting on to the plateau holes (#8-14) on #5-6-7 builds anticipation and the plateau holes feature some attack movement off the tee that really isn't found on Black. #15 and 16 are big holes on the scale of Black.