There is rarely one right answer. Here are several categories of pairing options, each with a reason it may work.
Alizarin Crimson
Similar lightness for a subtle, tone-on-tone pairing with minimal contrast.
Vermilion
Similar lightness for a subtle, tone-on-tone pairing with minimal contrast.
Rose Gold
Similar lightness for a subtle, tone-on-tone pairing with minimal contrast.
Terracotta
Similar lightness for a subtle, tone-on-tone pairing with minimal contrast.
Cherry Red
Enough lightness contrast to read as two distinct colours without feeling harsh.
Chestnut
Enough lightness contrast to read as two distinct colours without feeling harsh.
Firebrick
Enough lightness contrast to read as two distinct colours without feeling harsh.
Brown
Enough lightness contrast to read as two distinct colours without feeling harsh.
Taupe Grey
A low-chroma neutral lets the original colour stay the visual focus.
Grey
A low-chroma neutral lets the original colour stay the visual focus.
Silver
A low-chroma neutral lets the original colour stay the visual focus.
Graphite
A low-chroma neutral lets the original colour stay the visual focus.
Lime
A saturated accent from a different hue family for a deliberate pop of contrast.
Spring Green
A saturated accent from a different hue family for a deliberate pop of contrast.
Chartreuse
A saturated accent from a different hue family for a deliberate pop of contrast.
Lime Green
A saturated accent from a different hue family for a deliberate pop of contrast.