I never heard of these unlucky sayings. Glad my mom and dad didn't as they married in May and stayed that way for 67 years until dad died and my sister also in May and remained until her husband died after 55 years of marriage. Wonder if they would have picked another month if they knew of this saying!!'Marry in the month of May and you will surely rue the day' is an old English saying. It was supposedly unlucky from ancient times as there was a Roman festival for the dead held in the month of May.
Yes, green was considered unlucky for brides to wear as it was thought to be the colour of fairies and other supernatural beings, and they might come and carry her off!