There are no other colours that produce so much light and transparency. The pictures – the good ones – seem to be illuminated from behind.
The difficulty: It’s a game of three elements: Paper – water – colours. You may say: they are the same elements as with acrylics. Yes – but the difference is in the word “game”.
Many beginners are disappointed because the colour does not stay in the shape they want. Due to the amount of water in the paper it spreads in its own way. So it takes some time and a lot of practice to find out which amount of colour and which amount of water leads to the effect you want to see.