Bicycle inner tubes have branding text, logos, sizes etc written on them. You can choose whether or not you want your earrings or brooch to include some writing. Note that you will need to choose reasonably long earrings to be able to include a decent amount of text. I recommend medium or long earrings if you want text on them.
The photo shows, from left to right, altitude, airlock and parsons.
I don't recommend including text and colour as the colour will detract from the text.
You can choose to add colour to your jewellery if you want a flash of colour as they move and catch the light.
Choose between the following, showing from left to right across the photo: