There are several names i.e. Dominance of color a color harmony, color scheme, a blaze of color are all groups of colors
not as colorful as my brain
They are called analogous colours.
it is called a comet chameleon because it can change colours to the different colours in the comet
Silks.
Black, brown and grey.
A group of colours blending into each other.
I will assume the anniversary is for a group or city. Most such will have colours associated with them. As there is no specific colour used for the 130th , some combination of the colours used by the group would be appropriate.
These are primary colours because they are not man made, no two colours can be mixed to recreate these three colours.
Almandine
The primary colours are: Red, green and blue (RGB), any colours are made firstly by these colours and are called secondary colours: Red + Blue = Purple, Green + Red= yellow.
'Holi' is called the 'Festival of Colours'.
Opaque