Safranins is a type of dye that is used to color things red.
Using safranins to color things is a way to make them look pretty or interesting.
Examples:
She used safranins to dye the fabric red.
The safranins made the water turn red.
The safranins colored the flowers a bright red.
He accidentally spilled the safranins and turned his socks red.
The safranins turned the whole lake red!
The safranins made everything look like it was on fire.