You did not indicate the type of cab, but most likely you are referring to a pickup.
I think that 1955-1st was the same as 1954, as far as interior colors: Pearl Beige standard interior color and Pulsar Gray for deluxe cab interior. A few other interior colors are mentioned in the Tech Tip below. If you go to the 1954 DuPont reference sheets (a link is at the top of the year-column), you'll find other information about interior colors.
1947-55 Advance-Design Trucks Paint Colors Tech Tip There were also 4 different/additional two-tone interior color schemes (for regular cabs).
Jim Carter probably has has good matches for many interior colors.
