The minimum supply voltage for a ordinary 555 is 4.5V. Then you need a battery that is 6V or more when new.
I buy a garden light at The Dollar Store. It has a color changing LED that some fade slowly between many colors and others flash red, green then blue fast then slow then fading.
The LED has 3 LED chips and a microprocessor inside. The garden light comes with three 1.5V button battery cells, a current-limiting resistor and an on-off switch. It costs only $1.00 and its parts are worth much more.
I buy a cheapo white solar light at Wal-Mart for $1.00 and use its solar panel, AA battery cell holder and circuit board that boosts the 0.8V to 1.4V from the battery cell to about 4 volts and turns on the LED when it gets dark and charges the battery when there is light. I replace the white LED with the color changing LED adding a Schottky diode and filter capacitor. Of course I replace the very poor quality Chinese rechargeable battery cell with a good one.