Hi there

I am new at building WW-2, so I need some colour help.
I need to know the humbrol colour numbers for painting US Army uniforms.
I want to ad Verlinden 1100 “that way” and Verlinden 1686 “US tank riders” to a Sherman that I am building.
Can you please help me with the colours of the uniforms, boots and so on.

Try these three sites for a general guide (I cannot vouch for accuracy):

US Army Models - A guide to Painting
Hat Miniatures WW II Allies
WWII US M1941/43 Khaki Field Jacket

Search for the IPMS Stockholm website's paint conversion charts.

As I said, this is a basic guide. If you plan to get more serious about figure modelling you will probably want to start mixing your own tones.

It's a very broad subject that can't relly be answered in a brief bulletin board posting. Broadly, the M1941 uniform was brown wool trousers and shirt. The matching wool jacket was deemed a 'dress' uniform, and was ordinarily worn only in rear areas, or on leave. In the field, the Parsons jacket (named for the officer who designed it) was usually seen. It was a tan or light greenish color, and was cut much like a civilian windbreaker. Popular initially, it fell out of favor because it was not fully lined, and couldn't be closed tightly enough to keep out the wind (the similar tanker's jacket was fully lined with blanket material, and had knit wool closures at neck and cuffs, and many infantrymen tried to scrounge these). There was also a green herringbone twill cotton fatigue uniform issued for hot climates.
The M1943 uniform was a deep green or brownish green. The jacket was longer than the M1941 Parsons jacket. Early examples were in a shiny sateen fabric, though later issues had a drabber finish. It began to appear in mid 1944, mainly on troops newly arrived from the US, but became more common after January, 1945 as old uniforms were replaced.
The M1944 jacket was nicknamed the Eisenhower or Ike Jacket, as he was an early adopter. It was inspired by British Battledress, and was a waist length, usually brown wool item. It was most widely seen among rear area troops and only became common with infantrymen after the war ended.
Boots were russet leather. Belts were olive or tan webbing. Metal gear was No. 9 Olive Drab. If these colors seem maddeningly vague, you have to remember that uniforms were made by dozens of manufacturers, and colors did vary from batch to batch. Uniforms in service would fade, so the end result is a huge variety in apparent colors on troops in the field.
Search for websites that cater to Uniform collectors and military reenactment groups, and you'll get a better idea of what the range of colors seen on US Army uniforms was.