This diploma thesis studies the impact of protective finishing on the colour of textile, dyed with natural colours. A 100% cotton textile was dyed with a natural turmeric (curcuma) dye. Water and oil repellent inorganic-organic hybrid precursor fluoroalkyl-functional siloxane (FAS) was selected as protective finishing agent, and was applied to the cotton fabric surface after or during dyeing. Different surface analyses were carried out on the samples, such as oil repellency, colour measurements on the reflectance spectrophotometer before and after fifth and tenth laundering, colour fastness to rubbing, light and hot ironing using the grey and blue scales. The results showed that the order of application of FAS apreture is important for the colour and colour fastness. FAS applied during dyeing lowers the K/S value, increases its wash resistance, resistance to light and rubbing and decreases resistance to hot ironing.