These adorable cats – which are twins – showcase their contrasting blue and green eyes. The cats have a condition called heterochromia iridis, which causes each eye to vary in color. (Photo by @sis.twins/Caters News Agency)

Filipino Muslims pray outside the Blue Mosque as they celebrate Eid al-Fitr on May 13, 2021 in Taguig, Metro Manila, Philippines. Eid al-Fitr marks the end of Ramadan, during which Muslims in countries around the world spend time with family, offer gifts and often give to charity. Parts of the Philippines remain under strict lockdown to curb the spread of the coronavirus, with religious venues restricted to 20 percent capacity only. (Photo by Ezra Acayan/Getty Images)

English singer, who was a member of the British girl group “Little Mix” from 2011 to 2020 Jesy Nelson (L) looked incredible as she hit the beach in a black bikini with palsin the first decade of March 2022. The pop star, who is currently living it up in Malibu, let her hair down underneath blue skies on the west coast. (Photo by Instagram)

In this photo taken on January 20, 2024 a tourist poses in front of incense sticks drying in a courtyard in the village of Quang Phu Cau on the outskirts of Hanoi. Families living and working in the “incense village” of Quang Phu Cau now also make sticks in yellow, blue and green, catering to visitors eager to snap shots for Instagram. (Photo by Nhac Nguyen/AFP Photo)

A Australian green tree frog wearing a small turtle as a hat, keeping its head dry during its swim in Padang West Sumatra, Indonesia in May 2023. The Australian green tree frog grows up to 11 centimetres tall, the males being smaller that the females. They can live to the age of 25 and their colour alters between green, brown and blue depending on their mood. (Photo by Yan Hidayat/Media Drum Images)

A blue crab, a highly invasive alien species, is seen at Lio Piccolo during the reforestation day on April 05, 2025 in Venice, Italy. The island of Lio Piccolo in the northern lagoon of Venice is being replanted with 16,000 new trees that will protect the salt marsh ecosystem that is fundamental to the natural health of Venice and the lagoon by WOWnature project, an Etifor initiative. (Photo by Simone Padovani/Getty Images)

A student attending a winter military camp reacts during a training session in Ansan, south of Seoul January 3, 2013. Hundreds of students between 11 and 17 years old attend winter boot camp training courses every year. The winter courses range from 4 to 14 days at the Blue Dragon Camp run by retired marines, which also offers summer boot camp for students. (Photo by Kim Hong-Ji/Reuters)

Ngorongoro Crater (Tanzania). At 610m deep and 260 sq km, this is the largest unflooded caldera in the world. A blue-green vision from above it's a haven for engangered wildlife and Maasai livestock. The crater was formed three million years ago when a giant volcano, which could have been as high as Kilimanjaro, exploded and collapsed. The caldera formed the concentric fractures in the crust cracked down to a magma reservoir deep underground. (Photo by John Bryant/Getty Images)