This trophy can still be very tricky, even on Easy mode.
Before starting, make sure to change the difficulty to Easy on options as this game defaults to Normal difficulty.
There is a piece in this game called Magic Jewels which is a light blue shiny piece. When this is placed on a coloured jewel, it eliminates that colour from the game.
However, if you place it on the very bottom of the level such that there is no jewel below it, you get a point bonus instead of 10,000 points which is half of what you need for this trophy.
So while playing, keep the far right or far left column completely blank just in case one of these pieces comes along and then place it in the empty column. It is hard to get 2 of these pieces to come along however so you may have to work for the other 10,000 points.
This game can be hard as it speeds up but luckily you can use the pause menu and still see the jewels so use this to plan out your next move.
Luckily the game gives you more points the longer you stay in, by level 7, I was getting 240 pts per 3 jewels and an additional 480 pts for any combo.