okay! i've found out how to anodise Ti at home - seems very simple although to achieve different colours you'll bneed a higher voltage battery (I don't advise using mains
the colours achieved depend onthe voltage (see picture below) and the following link shows how to do it (achieving a purple colour from 9V
intersetingly enough Al anodized coatings have a much lower thermal conductivity and coefficient of linear expansion than aluminum. thus as a result, they will crack if exposed to temperatures above 80Â°C - something to be aware of in hot countries if you leave your bike in the sun maybe?