Both of these hair colors are mixed 2:1 or two parts developer to one part hair color. 4) The higher the number (or level) designated to the color, the greater its' lightening ability. 5) When mixing 2 colors at different levels, the higher level color will lighten while the lower level will add depth-helping to avoid brassiness. 6) When mixing 2 hair colors together, a simple mathematical formula to determine your resulting hair color level is: Add your natural hair color level to the level of the hair color you are using. For example: your natural level is a 5 (dark brown). 9 is the level of the hair color you are using. ( Level 5 + level 9) = 14. Then divide the sum total of the 2 levels (14) by 2. 14 divided by 2=7.
retighten (third-person singular simple present retightens, present participle retightening, simple past and past participle retightened) to tighten again.
airtight-not allowing air or gas to pass in or out. gas-tight, air-tight. tight-of such close construction as to be impermeable; a tight roof; warm in our tight little house.