Saratsuya (and) Straight (Hair), *サラツヤ/Saratsuya = sarasara+tsuyatsuya Sarasara means "smooth" and tsuyatsuya means "shinny". *すとれーと/sutorehto Means straight. So,サラツヤストレート means, Smooth and shiny straight hair. I see the word on hair products a lot. not really used for daily use of Japanese. I am guessing hair product company made the word for people to know what the product will do and what its used for. They needed a “One word explains all” kinda thing I guess. I see people use on TV shopping,Ad,market,magazine. you can still use it with friends too though. わ〜 あなたの かみのけ とても ツヤツヤ ですね！ "Wow your hair is so shiny!" そうでしょ！ きょうは サラツヤ(かみ）の ひ！ "I know! Today is Saratsuya-straight (hair) day!" カーリー で かわいい かみのけ が ほしい！ “I want curly and pretty hair” あのこ みたいに？ “like,that girl?” そうそう！ うらやましい！ “Yes yes! So jealous!” あなた の かみのけ は ツヤツヤ だから カーリーヘアー は とても きれい に できる と おもう！ “since your hair is so shinny,I think curly hair will turn out really beautiful!” hope this help,Jacqueline.

i believe it means something like sleek straight hair 艷やか(つややか）