There is rarely one right answer. Here are several categories of pairing options, each with a reason it may work.
Aquamarine
Enough lightness contrast to read as two distinct colours without feeling harsh.
Powder Blue
Enough lightness contrast to read as two distinct colours without feeling harsh.
Duck Egg Blue
Enough lightness contrast to read as two distinct colours without feeling harsh.
Seafoam Green
Enough lightness contrast to read as two distinct colours without feeling harsh.
White
Strong lightness contrast and saturation for a bold, graphic pairing.
Black
Strong lightness contrast and saturation for a bold, graphic pairing.
Mint Cream
Strong lightness contrast and saturation for a bold, graphic pairing.
Off-White
Strong lightness contrast and saturation for a bold, graphic pairing.
Azure
A low-chroma neutral lets the original colour stay the visual focus.
Honeydew
A low-chroma neutral lets the original colour stay the visual focus.
Mint Cream
A low-chroma neutral lets the original colour stay the visual focus.
Ash Grey
A low-chroma neutral lets the original colour stay the visual focus.
Claret
A saturated accent from a different hue family for a deliberate pop of contrast.
Tyrian Purple
A saturated accent from a different hue family for a deliberate pop of contrast.
Ruby
A saturated accent from a different hue family for a deliberate pop of contrast.
Cerise
A saturated accent from a different hue family for a deliberate pop of contrast.
Black
Meets WCAG AA contrast (16.7:1) for normal text if used as text/background.
Navy Blue
Meets WCAG AA contrast (12.8:1) for normal text if used as text/background.
Midnight Blue
Meets WCAG AA contrast (11.8:1) for normal text if used as text/background.
Prussian Blue
Meets WCAG AA contrast (10.7:1) for normal text if used as text/background.