There is rarely one right answer. Here are several categories of pairing options, each with a reason it may work.
Vermilion
Similar lightness for a subtle, tone-on-tone pairing with minimal contrast.
Tomato
Similar lightness for a subtle, tone-on-tone pairing with minimal contrast.
Alizarin Crimson
Similar lightness for a subtle, tone-on-tone pairing with minimal contrast.
Red
Similar lightness for a subtle, tone-on-tone pairing with minimal contrast.
Cadmium Red
Enough lightness contrast to read as two distinct colours without feeling harsh.
Crimson
Enough lightness contrast to read as two distinct colours without feeling harsh.
Cherry Red
Enough lightness contrast to read as two distinct colours without feeling harsh.
Ruby
Enough lightness contrast to read as two distinct colours without feeling harsh.
Black
Strong lightness contrast and saturation for a bold, graphic pairing.
Prussian Blue
Strong lightness contrast and saturation for a bold, graphic pairing.
Gunmetal
Strong lightness contrast and saturation for a bold, graphic pairing.
Tyrian Purple
Strong lightness contrast and saturation for a bold, graphic pairing.
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.
Lavender Blush
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.