How does one acquire a yellow belt?

Classifieds at time of posting:

1x 4.88 ref

rest at 5 ref

Sellers at or below 5 ref:

http://www.tf2outpost.com/trade/23432179 2 ref (click the first comment, he's willing to let it go for 2 ref.)

http://www.tf2outpost.com/trade/23522096

http://www.tf2outpost.com/trade/23605906

http://www.tf2outpost.com/trade/23645360

http://www.tf2outpost.com/trade/23649648

http://www.tf2outpost.com/trade/23120393

http://www.tf2outpost.com/trade/23647076

http://www.tf2outpost.com/trade/23618557

Unsolds above 5 ref:

http://www.tf2outpost.com/trade/23366853 "bp.tf price" 2 wks

http://www.tf2outpost.com/trade/23243709 5.66, 3 weeks

http://www.tf2outpost.com/trade/23182358 6 ref, 3 weeks

http://www.tf2outpost.com/trade/23355985 6.33, 2 weeks

http://www.tf2outpost.com/trade/23333255 8 ref, 2 weeks

http://www.tf2outpost.com/trade/23283929 8 ref, 2 weeks

http://www.tf2outpost.com/trade/23317635 8 ref, 2 weeks

http://www.tf2outpost.com/trade/23257831 8 ref, 3 weeks

http://www.tf2outpost.com/trade/23234966 8 ref, 3 weeks

http://www.tf2outpost.com/trade/23222155 1 key, 3 weeks

http://www.tf2outpost.com/trade/23218528 1 key, 3 weeks

http://www.tf2outpost.com/trade/23243297 1 key, 3 weeks