Colias tyche, the Booth's sulphur or pale Arctic clouded yellow, is a butterfly in the family Pieridae.

It is found from Baffin Island west along the Hudson Bay and arctic coasts of the Nunavut and Northwest Territories mainland and the southern tier of Arctic Islands to northern Yukon, Alaska, and Eurasia.

[1]is a small to medium-sized Colias butterfly with pale green to greenish-white or greenish-yellow wings, more or less suffused with grey-green in the basal part of the hindwings and very visible brown veins.

The dark borders are wider in the female and encompass a submarginal line of pale yellow spots bordered with black in the male, black spotted with yellow in the female.

Colias philodice vitabunda females are often white.The underside is greenish very marked with dark scales.