Generally, crickets have yellowish-brown to brown color. Some may have black color. There are rare chances that you will find different colored cricket.
Why are my crickets turning white (Albino Crickets)?
Crickets turns white when they molt. These white crickets are referred as albino cricktes. Generally, crickets are brown in color but when they molt they get new soft, milky white exoskeleton. After few hours of molting they will start turning dark brown like other crickets.
Crickets grows from being pinhead size to the size of 1-2 inch. While growing their exoskeleton (outer layer) stop their growth. At this stage they are not a full grown adult but in phase to grow.
Since exoskeleton stop the future growth, they start sheding the outer layer. This process is called as molting. Once cricket molt thier outer layer they keep growing until they becomes adults.
Adult crickets do not grow further or molt.
But once cricket molt and shed their hard exoskeleton, they gets a new, soft exoskeleton which is soft in nature and looks milky white in color due to which these crickets look white in color and oftenrefered as albino white.
But this phase of being white remains for awhile in crickets life afterwhich they turn into brown color as exoskeleton becom hard.

How often do crickets molt?
In order to grow naturally, cricket nymphs has to molt around 8 to 10 times. Cricket nymphs are young and tiny version of adult crickets. Molting helps them to grow into adult cricket.
Are albino crickets rare?
Albino crickets are not common. Cricket nymphs turns white during their growing phase when they shade their hard exoskeleton and regain the new one which is soft and milky white.
Fun Fact – The albino cricket or white cricket insect symbolizes someone you love, returning back into your life.