NHS
The NHS page on hair dye allergy, symptoms, precautions and what to do on suffering a reaction:
https://www.nhs.uk/conditions/hair-dye-reactions/
British Association of Dermatologists
A website with resources and information on topics including patch tests and contact dermatitis:
The British Association of Beauty Therapy & Cosmetology.
A useful resource for finding trained and qualified beauty therapists:
https://www.babtac.com/consumers
Allergy UK
A charity dedicated to supporting those with allergies:
Anaphylaxis Campaign
Supporting people at risk of severe allergies:
https://www.anaphylaxis.org.uk/
Wella Stories - Colour
Blog posts on a variety of hair colouring topics.
https://blog.wella.com/gb/filters/colour
Josh Wood Colour
Tips, tricks and advice on colouring hair.
https://joshwoodcolour.com/blogs/advice
L’Oréal Hair Colour Advice
Articles on hair colour terminology and techniques.
http://www.lorealprofessionnel.co.uk/hair-advice/hair-colour-advice