Honeylocust (Gleditsia triacanthos) seeds have hard seed coats of different colours that affect duration of dormancy. This study investigated the effects of seed coat colour on water uptake, germination, and quantity of seed parts. The results show that seed coat colour had a significant effect on seed moisture content, seed coat weight, endosperm weight, water uptake, and germination. However, the quantity of embryos having seed coats of various colours did not differ significantly. Seeds with a yellow seed coat contained the most moisture and had the highest water uptake, even though yellow seed coats were thicker than other coat colours. Yellow-coated seeds showed 100% imbibition after 48 h and also the highest germination (95%). As honeylocust seed coats darken, it slows down seed germination. This research suggests that yellow-coated honeylocust seeds should be recommended for nursery cultivation.