What you require, the colours to be permanent and water/heat-resistant, glazing is the straight way to go. DEEP SPACE SPARKLE glaze tints, shades and uneven tones

DEEP SPACE SPARKLE is Cone 06 oxidation aventurine glaze that looks as high fired reduction stoneware glazes. Aventurine effects and other reduction surfaces are achieved with no price tag or trouble of high fire reduction. It's an unusual and interesting glaze and provides suitable results after applied thickly and fired on flat surfaces. On vertical surfaces and narrow application, the achievements will vary. The color in the clay will not prove through where there is texture but adds dimension to the glaze. Due to the fact of this effect, individuals glazes will look completely alternative.

How to use Artistic Glazes (Aventurines): 

Liquid glaze is very good for brush on. It really should be coated 2-3 times with a gentle brush when the first fire. When drying please fire between 940-1000°C. Shake and stir very well before to use. If the glaze becomes thickened higher than time easily add water and stir thoroughly.

Dry glaze is to be dissolved in water to a thick paste which must be thinned to the correct density. Each glaze is suggested to be tried with different layers on the body concerned and under decided conditions.  The mixing of the glazes is possible in order to swap color shade, melting properties or to reach few artistic effects. Once in a while, the glaze coat can crawl due to the presence of dust, grease or dirt on the bisque. Glazed pieces have to be well dried prior to the lighting. The firing temperature should correspond to the given information. 

Quantity: 40 g. (1,41 oz.) 
Firing temperature: 940-1000°C (1700-1830° F) (up to Cone 06) 
Surface: Gloss
Luminescence: cover (opaque)
Lead content: lead-free, 0%

What is a glaze, what is antiquing and other Q/A for painting and glazing can be found in the section: Paint and Glaze.