import re
str = 'color-purple, designer-allison_parris, formality-6, sizescale-us_combined, type-dress'
match = re.search(r'.*?color-(\w+).*', str)
if match:
print match.group(1)
aW1wb3J0IHJlCgpzdHIgPSAnY29sb3ItcHVycGxlLCBkZXNpZ25lci1hbGxpc29uX3BhcnJpcywgZm9ybWFsaXR5LTYsIHNpemVzY2FsZS11c19jb21iaW5lZCwgdHlwZS1kcmVzcycKbWF0Y2ggPSByZS5zZWFyY2gocicuKj9jb2xvci0oXHcrKS4qJywgc3RyKQoKaWYgbWF0Y2g6CiAgICBwcmludCBtYXRjaC5ncm91cCgxKQ==